Kemba Walker plans to be in Boston on Sunday to finalize a formal agreement for a four-year, $141 million deal with the Celtics, league sources told ESPN's Adrian Wojnarowski on Saturday.

The Celtics have targeted Walker, 29, as the No. 1 priority in free agency and an elite replacement for the departing Kyrie Irving, sources said.

NBA free agents can begin negotiating agreements with teams at 6 p.m. ET Sunday. Contracts can be officially signed July 6.

Walker is coming off his best season as a pro during his eight seasons with the Charlotte Hornets, averaging 25.6 points while playing in all 82 regular-season games.

After a season of locker room turmoil often centered around Irving's discontent, the Celtics crave the stability and leadership that Walker will provide -- along with being an All-Star talent in the prime of his career.

Boston can renounce the rights to restricted free agent Terry Rozier to clear the space to start Walker on a four-year deal beginning at $32 million annually.

Walker can plug into a Celtics lineup that includes Jayson Tatum, Gordon Hayward and Jaylen Brown. Boston can still pursue a center with its $4.8 million exception and deliver at the start of the season a team that could be competitive in the Eastern Conference.

Charlotte, meanwhile, has declined to exercise its qualifying offer on Frank Kaminsky, allowing him to become an unrestricted free agent amid significant interest, a league source told ESPN.

The Hornets have been scouring the free-agent point guard market, considering such options as Elfrid Payton, T.J. McConnell, Ish Smith and Emmanuel Mudiay, league sources told ESPN.

Walker won a national championship at UConn in 2011 and is a New York City native.

New York Yankees first baseman Luke Voit left Saturday's 17-13 win over the Boston Red Sox in London due to what he described as a "lower abdominal" injury.

Voit said the injury wasn't to his groin or his hip and that he'll see how he feels on Sunday, and that will determine whether tests are needed.

"A little tightness, but nothing crazy," Voit said of how he felt following the series opener. "It kind of freaked me out when it happened. I guess there was really no point to me staying in the game, so that [getting taken out] was the right decision."

Voit doubled to lead off the fifth inning but said he felt tightness while rounding first base and then hobbled into second.

He would have been out at second, but Boston second baseman Brock Holt dropped the ball after applying the tag.

Gio Urshela ran for Voit and later scored.

Voit went 4-for-4 on the day with three doubles. Urshela stayed in the game at third base, and DJ LeMahieu moved across the diamond to replace Voit at first.

Manager Aaron Boone noted Voit's postgame physical exams "were all good." Still, he did acknowledge that he was a little uneasy about the injury.

"Sure it's a concern," Boone said. "[But] I feel like the evaluation of him was pretty good considering what I saw. And even when I went out there, he said, 'Actually, I think I'm OK.'"

The Red Sox, meanwhile, lost shortstop Xander Bogaerts to a left leg cramp. Bogaerts felt the cramp running the bases in the seventh inning but remained in the game before being replaced by Edwin Nunez in the top of the eighth.

ESPN's Coley Harvey contributed to this report.

DENVER -- Hey, blue, great call!

Major league umpire Chris Guccione invited a teenage ump who was involved in a game that ended in an adult brawl to attend the Dodgers-Rockies series finale Sunday at Coors Field.

Guccione and his crew just wanted to show their support for 13-year-old Josh Cordova, who found himself in the middle of a recent fight in Lakewood, Colorado. Authorities said the skirmish at a game between teams of 7-year-olds began when parents and coaches disagreed with the teen's decisions. The video of the conflict went viral.

These adults took over the field and began assaulting each other on 6/15 during a youth baseball game. We're looking for any info, in particular to ID the man in the white shirt/teal shorts. Several people have already been cited in this fight and injuries were reported. pic.twitter.com/ieenhwCrbU

— Lakewood Police (@LakewoodPDCO) June 18, 2019

"It is an extremely hard job to be an umpire and keep the peace and to make the calls," said Guccione, who is from Colorado and in his 20th season as a big league ump. "I just want Josh and his family to have a great time at the ballpark."

The family was brought in through UMPS CARE Charities, the official philanthropy of MLB umpires.

"The support has been amazing," said Jennifer Carriera, Josh's mother. "We are really looking forward to this experience."

Milwaukee Brewers star Christian Yelich has thrown his name in the hat for the Home Run Derby.

Yelich, who leads the majors with 29 home runs, said Saturday night that he accepted an invitation from Major League Baseball to compete in the All-Star event on July 8 in Cleveland. The event will be televised on ESPN.

"They asked if I would do it a few weeks ago," Yelich said Saturday night after Milwaukee beat the Pittsburgh Pirates 3-1. "I said as long as I was an All-Star I would do it -- obviously if I'm feeling healthy enough before the game."

Yelich, the reigning National League MVP, was the NL's leading vote-getter for the All-Star Game. He is slashing .327/.423/.704 with 63 RBIs.

Yelich joins New York Mets rookie Pete Alonso as confirmed participants as the field begins to round out, meaning the competition will feature MLB's two leading home run hitters. Alonso is second in the majors with 28 homers.

"I feel like now's as good a time to do it as any, so we'll see how it goes," Yelich said.

Philadelphia Phillies star Bryce Harper won last year's Home Run Derby.

The Associated Press contributed to this report.

CINCINNATI -- There aren't likely to be any Christmas cards exchanged between Chicago Cubs pitcher Pedro Strop and Cincinnati Reds outfielder Yasiel Puig after the two had words with each other as the benches cleared in the Cubs' 6-0 win on Saturday.

Puig got hit in the hip by a 3-0 pitch from Strop in the bottom of the eighth inning and began to walk toward the mound while screaming at the pitcher. Cubs catcher Willson Contreras and first baseman Anthony Rizzo held Puig back while Puig and Strop kept yelling at each other. Things eventually calmed down, and after the game, Strop didn't understand why Puig was so upset.

"He just reacted like that," Strop said. "Maybe because it was a 3-0 pitch, maybe it looks weird. I wasn't commanding my sinker, and I didn't want to leave a cookie 3-0. He'll swing 3-0 and hit it way out of the park. He just acted stupid."

Strop wasn't finished with Puig. The righty was asked what he was yelling at the outfielder as the two were kept separated.

"I told him, 'Why are you talking?'" Strop said. "'You have a chance to do whatever you need to do on the mound. Now you're just screaming.'

"It's not a secret he's stupid. He's stupid as f---. I have nothing against him, but he's stupid. There's no doubt about it."

Puig told reporters that he hasn't had any previous issues with Strop and wasn't sure why he was hit with a 3-0 pitch.

"I don't know. You need to ask [Strop]," Puig said. "Myself and my teammates want to go out tomorrow and win the series. ... We'll play the game tomorrow and forget about what happened today."

Neither player got ejected from the game, as Puig took first base before Strop ended the inning by striking out Jose Iglesias. Reds manager David Bell did get tossed in the ninth inning, when Cubs righty Dillon Maples hit Reds infielder Jose Peraza without any punishment from the umpires.

Bell said he was asking why Maples was not ejected after both teams had been warned and was told that the pitch that hit Peraza was unintentional. It was Bell's sixth ejection of the season.

"The bottom line is I don't like it when our players get hit,'' Bell said.

Strop said there is no history of bad blood between him and Puig, and Cubs manager Joe Maddon stressed that Puig got hit in the hip -- not up high.

"I told Strop he threw his three best sliders of the year after that, to Iglesias, so he rose to the occasion," Maddon said.

The Associated Press contributed to this report.

In 2017, the Denver Post profiled Tony Cowell, the Coors Field stadium engineer who -- inspired by an uncomfortable pair of leather hunting boots -- conceived of a humidor that would bring Coors Field's extraordinary offensive environment to heel.

"People were disparaging Coors Field, and that really bothered me," Cowell said in that profile. "Look, I knew that baseball here wasn't really normal big league baseball. I wanted to do something about that."

The humidor worked. According to Baseball Reference, Coors Field's Three-Year Park Factor -- a measure of how much offense a park allows, relative to other parks -- was 125 from 1999 to 2001, or 25 percent more conducive to scoring than other parks. From 2002 to 2004, that park factor dropped to 115, and it kept sinking. From 2006 to 2008, offense was just 7 percent higher than average. We all generally accept that the humidor has, as Cowell put it, "normalize[d] things a little bit."

This week, the Los Angeles Dodgers -- with one of the greatest starting rotations in baseball history -- visited Colorado. Walker Buehler started the Thursday night game, coming off a 16-strikeout, no-walk, complete game against the Rockies in Los Angeles the previous Sunday. In June, Buehler had 42 strikeouts and one walk, with a 0.87 ERA in four starts. But he got rocked at Coors Field, allowing 13 hits and seven runs. Then Hyun-Jin Ryu started Friday, entering the game with a 1.27 ERA. He couldn't get an out in the fifth inning before he was replaced, having allowed seven runs. Four innings at altitude made his ERA jump almost 50 percent.

It took 18 seasons after Cowell's miracle cure for altitude, but Coors Field has fought back. Its Park Factor has been steadily rising, and this year it has reached a new post-humidor extreme. Nothing in that park is normal anymore. To put baseball in Colorado in perspective, here are 18 facts about Coors Field this year. Some of these have bright-red "Small Sample!" flags, but they're all a wonder to say aloud:

1. At Baseball-Reference, Coors' Multi-Year Park Factor (which includes this year and last) is 120, the highest it has been since the humidor was installed. ESPN publishes a simpler, single-season Park Factor, and according to that measure, Coors Field this year has the highest park factor for scoring since at least 2001, the final pre-humidor season.

2. Through Friday night, Charlie Blackmon was hitting .468/.518/.984 at home and .236/.272/.382 on the road. His tOPS+ -- which compares a player's OPS in one split to his performance overall, with 100 representing average -- was 190, the second highest in major league history for a player with at least 100 home plate appearances. More on him later.

3. The Rockies have scored at least 10 runs nine times this season and have allowed at least 10 runs 11 times. Of those 20 games, 17 were at Coors Field.

4. The Rockies hitters have a tOPS+ (which, again, is their OPS in this split relative to their OPS overall) of 135 this year. That's the second-highest team tOPS+ in Rockies history -- and in all of major league history.

5. Rockies pitchers have the third-highest tOPS+ in franchise history (and the third-highest in major league history). The two years that were more extreme for Rockies pitchers are actually different than the one year that was more extreme for Rockies hitters, so there has never been a season when both pitchers' and hitters' tOPS+ were higher than for this year's Rockies.

6. Wade Davis, the Rockies closer, is rumored to be on the brink of losing his job as the closer. Justifiably, considering he has a 6.00 ERA overall. His road ERA, though, is 0.79. His home ERA is 10.66.

7. Kyle Freeland, who finished fourth in Cy Young voting last year, is in Triple-A after a spectacular decline this season. On the road, he had a 5.04 ERA and allowed a .242/.324/.467 line. That's not great, but not typically enough to get an Opening Day starter sent to Triple-A. At home, however, he had a 9.31 ERA and a .317/.375/.618 batting line against him.

8. On balls hit in the air (line drives, fly balls and popups), Rockies hitters are hitting 105 points higher and slugging more than 230 points higher at home than on the road. Meanwhile, Rockies pitchers are allowing a batting average 109 points higher and a slugging percentage 280 points higher at home.

9. Even ground balls are far more likely to be hits in Colorado: Rockies hitters and their opponents have hit .258 at Coors on grounders this year. Rockies hitters and their opponents have hit just .211 on grounders everywhere else.

10. Pat Valaika was hitting .267/.421/.533 at home in 19 plate appearances. In 29 road plate appearances, he was hitting .000/.069/.000.

11. Rockies pitchers have a 3.90 ERA on the road, which is the fourth-lowest mark in baseball. Just to rephrase that so it is extremely obvious and extremely clear: Once the effect of the home ballpark is stripped away, the Rockies arguably have had the fourth-best pitching staff in the majors, or at least the second best in the National League. Those same pitchers have a 6.45 ERA at home, which is the second-worst home ERA since at least integration (better only than the 1999 Rockies). The Rockies are 23-16 at home and just 20-23 on the road.

12. Rockies pitchers have struck out fewer batters at home, but it's not a huge difference; and they've also walked slightly fewer batters at home. Indeed, almost all of the difference for their pitchers is on batted balls -- and what happens to those batted balls. Their FIP -- which focuses only on strikeouts, walks and home runs, and estimates what ERA should be -- is 5.13 at home road and 4.44 on the road, a much smaller gap than in ERA. By xFIP, which focuses only on strikeouts, walks and fly ball (rather than home run) rates, there's virtually no difference: 4.57 at home and 4.36 on the road.

If Rockies pitchers were giving up way more hard contact, that would be easily explained, but they actually have allowed a lower exit velocity at home, and according to Statcast's xwOBA (.346 at home, .337 on the road), they've allowed similar quality of contact. Quality of contact is more complicated than that, but all of this together suggests that Rockies pitchers aren't pitching worse at home, but that the same batted balls are doing far, far, far more damage in Colorado.

13. But to go back to Blackmon: Blackmon, remember, is the best hitter in baseball at home and has been pretty mediocre on the road. (The extremeness of Coors Field doesn't just help hitters; it seems to hurt those same hitters when they go on the road.) For him, every thing is better at Coors. He has an exit velocity 5 mph higher at home. His xwOBA is .446 at home and .292 on the road. (His actual wOBA is .594 at home. Barry Bonds' best-ever wOBA was .544.) Blackmon has struck out 50 percent more often on the road, and he has walked only a quarter as often. He chases pitches out of the strike zone more often on the road, and he makes contact less often on the road.

14. On breaking balls, Blackmon is slugging .471 on the road, but 1.121 at home.

15. On fastballs, he is slugging .296 on the road, 1.123 at home.

16. The median ballpark allows a .359 wOBA on fastballs, and 15 ballparks are within 10 points of that. Coors Field has allowed a .415 wOBA on fastballs, 23 points higher than the next stadium.

17. Left-handed pitchers at Coors Field have an ERA of 8.19 this year. Batters (on either team) are hitting .343/.413/.610 against them.

18. Why? That's more complicated -- and a subject for another article (pending, perhaps, a few more months to see whether this regresses to less extreme levels, as Valaika's line surely will). The simplest hypothesis would be that when leaguewide offense is up -- as it is now, thanks to MLB's livelier ball -- it affects Coors Field most of all. But since 2001, there hasn't been any statistical correlation between Coors Field's single-year Park Factor and MLB's overall offensive environment.

That doesn't rule out a connection: Baseball is profoundly weird right now, and nearly every on-field trend ultimately can be linked to either rising strikeouts or rising home runs (or both). Coors Field also is profoundly weird right now, and the two might ultimately be linked. But altitude has been one of the most persistent forces in baseball since the Rockies' first game in 1993. Maybe altitude will always find a way.

Middle-distance man Jake Wightman back from injury to beat strong domestic 800m field at BMC Grand Prix while Sarah McDonald and Andy Butchart also enjoy good victories

Jake Wightman took the honours in the much-anticipated men’s 800m race on Saturday night at Watford, but on Britain’s hottest day of the year there were masses of PBs in 28 races, making it one of the best BMC meetings in history.

Wightman had not raced on the track since last August due to a stress fracture of the sacrum but he made a sensational comeback. Holding back from the fast pace (51.28 at the bell) he took control in the last 200m to win in 1:45.55.

Charles Da’Vall Grice finished strongly to finish second in 1:45.72 from Elliot Giles third in 1:45.80 with Spencer Thomas fourth in an one-second PB with 1:46.19 as the Brighton Phoenix athlete celebrated his European under-23 selection.

In the B race there were big breakthroughs for juniors Oliver Dustin and Joshua Lay. Dustin won in a PB 1:46.84 while Lay ran 1:47.93 in what has easily been the greatest year in British junior 800m history.

Britain currently has the fastest five juniors in Europe, led by Max Burgin, the Halifax athlete who ran 1:45.36 in Bedford the previous weekend.

Behind Dustin and Lay, Alex Botterill was third in 1:47.93 and another junior, Ben Lee, won the C race in 1:49.36. Even in the D race, two juniors excelled with Callum Dodds clocking 1:49.17 and Daniel Howells 1:49.34.

Sarah McDonald showed superb 800m speed to win the women’s A race in a PB 2:00.15 with a strong last 200m.

Alex Bell ran 2:01.36 and European indoor champion Shelayna Oskan-Clarke 2:01.47 to complete the top three.

The women’s 800m B race, meanwhile, was won by Finland’s Sara Kuivisto in 2:02.64.

The men’s 1500m saw a strong finish from Olympic 5000m sixth-placer Andrew Butchart, who won in 3:38.84 to overhaul James McMurray, who ran 3:39.02.

Under-23 runners Archie Davis (3:40.30) and George Mills (3:40.30) both had breakthrough runs.

Butchart then paced the 5000m which was won by Hillingdon’s Mohamed Mohamed in 14:07.25.

The women’s 1500m was won by Denmark’s European under-23 champion Anna Emilie Moller in 4:09.15 as Jess Judd finished strongly to take second in 4:10.74.

Judd then paced the women’s 5000m which was won by Emily Hosker-Thornhill in a PB 15:46.22 as Amelia  Quirk finished second in 16:02.54.

European under-18 champion Thomas Keen won an exciting under-20 men’s 3000m that was labelled as a trial for the European Under-20 Championships in Sweden.

Eighteen athletes were in contention at 2000m but Keen kicked in a hard penultimate lap and although he weakened down the backstraight when Max Heyden kicked past he rallied in the straight to win in 8:18.41 from Heyden’s 8:18.82 as nine athletes broke 8:30.

The event saw probably the most exciting men’s 3000m steeplechase with the best depth in BMC history as nine athletes broke nine minutes and five went sub-8:50.

Chris Perry took almost 10 seconds off his PB to win with a fast last lap in 8:44.55 with Jayme Rossiter second in 8:46.81.

The women’s 3000m, mostly made up of juniors, was won by Katie Holt in 9:15.34. Behind her there was a huge breakthrough for under-20 Saskia Millard, who ran 9:20.82, a time which will surely confirm her European under-20 selection along with Eloise Walker, who ran 9:21.96 – well inside the 9:30 qualifying time for Sweden.

Ireland’s Michelle Finn was an easy winner of the women’s 3000m steeplechase in 9:51.22.

The final race of the day also saw an Irish win as under-20 Darragh McElhinney showed a good last lap kick to win the 3000m men’s A race in an Irish junior record of 8:01.48 ahead of Jonathan Davies.

The next stop on the Diamond League circuit looks like being one to remember

There have already been some excellent Diamond League meets this season, but the standard of the line-ups for Sunday’s Prefontaine Classic suggest that even better could lie in store.

With the usual Eugene venue of Hayward Field undergoing renovations for the 2021 World Championships, the event has moved 500 miles south to Stanford in California.

Caster Semenya is set to make a controversial return to the 800m following a temporary court action suspending the IAAF’s rules on gender regulation. The 800m field also includes Ajee Wilson, the American who lies second on the world rankings in 2019.

Sha’Carri Richardson, who burst on to the scene with her 10.75 world junior 100m record to win the NCAA Championships earlier this month, makes her Diamond League debut in a field featuring twice Olympic champion Shelly-Ann Fraser-Pryce, Marie-Josée Ta Lou, Aleia Hobbs and Kayla White.

Meanwhile, Britain’s Dina Asher-Smith looks to extend her unbeaten run over 200m this year to three meetings, facing double Olympic champion Elaine Thompson, who beat her over 100m in Rome before clocking 10.73 to win her national championships, plus Blessing Okagbare, Jenna Prandini and Dafne Schippers.

Rai Benjamin takes on Kerron Clement, Yasmani Copello and Kyron McMaster at 400m hurdles, while the men’s 400m sees Michael Norman, who ran 43.45 in April, take on Fred Kerley, who has run 43.70 and won in Shanghai, plus a returning LaShawn Merritt.

After her recent second place behind Genzebe Dibaba in Rome, Laura Muir will be aiming to continue her good form in the non-Diamond League 1500m. The Brit will meet Olympic champion Faith Kipyegon, last year’s winner Shelby Houlihan (below) and Ethiopia’s Gudaf Tsegay, who has run sub-four this year.

Dibaba will step up to the 3000m to face a great field. Sifan Hassan, who ran her close in Rabat, is also in the line-up, along with world champion Hellen Obiri, world 10,000m record-holder Almaz Ayana and Britain’s Laura Weightman.

The Bowerman Mile has a stellar line-up which includes indoor world record-holder Yomif Kejelcha, world 1500m champion Elijah Manangoi and two-time defending Diamond League champion Timothy Cheruiyot. Double European champion Jakob Ingebrigtsen, Olympic 1500m champion Matt Centrowitz and world indoor 1500m champion Samuel Tefera are also on the start lists.

In the rarely run two miles, Diamond League 5000m champion Selemon Barega defends his title, while world record-holder Beatrice Chepkoech and world champion Emma Coburn headline the women’s 3000m steeplechase.

Britain’s European champion Zharnel Hughes takes on world No.1 Christian Coleman and world champion Justin Gatlin in the 100m, with all eight men in the field having sub-10 second PBs.

The men’s shot put features the top four in the world this year, led by Ryan Crouser, while world and Olympic champion Omar McLeod heads the 110m hurdles line-up.

Russian high jump queen Mariya Lasitskene faces Yuliya Levchenko of Ukraine, while Renaud Lavillenie, Armand Duplantis and Sam Kendricks head a formidable pole vault line-up.