LATE IN GAME 4 of the Timberwolves' first-round series against the Phoenix Suns, with Minnesota looking to secure the sweep, Wolves guard Nickeil Alexander-Walker knew he had to make a play.

It was April 28, and Minnesota was clinging to a 113-111 lead in the final minutes. After a missed 3-point attempt from the Wolves' Mike Conley, the Suns had a chance to tie or take the lead to extend their season.

Alexander-Walker watched as Devin Booker threw a pass to Kevin Durant, who got doubled in the post. Durant tossed it back out to Eric Gordon, who swung it to Bradley Beal in the left corner as Durant slipped back to the right.

As the sequence developed, Alexander-Walker made the type of play his coaches and teammates now trust him to make: He saw Durant open after Karl-Anthony Towns cut off a driving Beal in the lane, and as Beal let a bounce pass go in Durant's direction, Alexander-Walker stretched out his arm for the tip and the steal.

Sixteen seconds later, Anthony Edwards detonated at the rim for a dunk on Durant that pushed the Wolves' advantage to a two-possession game. Minnesota never led by less than four again in completing the sweep.

"I think that play right there was like, 'I'm going to win this game and impact it as best as I can,'" Alexander-Walker tells ESPN. "Before it was like, 'Man, I don't got it going. I'm trying to find it.' Now it's like, 'I'm going to impact this no matter what.'"

After playing for three NBA teams in five years, the 25-year-old Toronto native who arrived in Minneapolis at the 2023 trade deadline has shown why he's a key part of the Wolves' hopes to advance from the Western Conference semifinals against the top-seeded Denver Nuggets.

"He's been one of our best players in the playoffs so far, and a lot of it has been his mental side," Conley tells ESPN. "He's really worked on that a lot. He's not letting anger take over, not letting past mistakes take over the next play.

"When he's 100% on that, man, he's one of our better X factors for our team."

ALEXANDER-WALKER HAS quietly turned himself into one of the NBA's best defensive players.

His journey has been anything but linear. As a rookie out of Virginia Tech with the New Orleans Pelicans in 2019-20, Alexander-Walker held opponents to 48.4% shooting as the contesting defender. That ranked 288th out of 317 players who defended at least 250 shots.

Alexander-Walker was initially billed as a bench scorer but quickly struggled to find rhythm in his first two years. Midway through his third campaign in New Orleans, the team dealt him to the Portland Trail Blazers. He thought it could be a much-needed free start, but he was quickly traded again to a competitive Utah Jazz team, which meant he'd be spending more time on the bench.

"I almost felt like I had missed the window for my career," Alexander-Walker admits. But now, he looks at it completely differently. "I think New Orleans (trading) me was the best thing that could have ever happened. It taught me how to be a man. How to be a true professional.

"Through the ups and downs of it all, I learned the only thing I have is my work."

While in Utah, Alexander-Walker's mindset shifted. He realized he was going to have to become more of a defensive player. In limited minutes in 2022-23, he held opponents to 40.9% shooting as the nearest defender. He knew that if he was to have a long future in the NBA, he would need to prioritize the dirty work.

Two days before the 2023 trade deadline, Alexander-Walker was on the move again.

As a part of a three-team deal with the Los Angeles Lakers and the Timberwolves that involved Russell Westbrook and D'Angelo Russell, the Jazz sent Conley and Alexander-Walker to Minnesota.

Alexander-Walker was a throw-in, conventional wisdom indicated, a player whose salary satisfied the mundane rules of the collective bargaining agreement.

When he arrived in Minnesota, there were familiar faces: Conley, Rudy Gobert and several staffers who were previously with New Orleans, including Wolves coach Chris Finch, who didn't always have the rosiest relationship with Alexander-Walker.

"Me and him were butting heads because of my eagerness in a certain way as a rookie for what I was wanting for my career," Alexander-Walker says.

The two hadn't spoken since Alexander-Walker left New Orleans, and he wasn't sure if Finch knew about the progress he made as a defender. But Alexander-Walker was relieved to find out that both Finch and Wolves president Tim Connelly did know -- and they hoped it was something he would continue to develop in Minnesota.

"It takes a while for everyone to kind of figure out who they are in this league," Finch tells ESPN. "As a young player, I watched him go through many frustrations, but this is who we always felt he could be.

"Even back in New Orleans, we always thought this was who he could be."

A SINGLE PUNCH would provide Alexander-Walker the opening he needed in Minnesota.

On April 9, 2023, the Timberwolves and the Pelicans entered the regular-season finale tied in the standings at 41-40. They played at Minneapolis' Target Center, with the winner getting the No. 8 spot and the Lakers in the play-in tournament, while the loser would fall to No. 9 and face the Oklahoma City Thunder.

Late in the first quarter, after picking up his second foul, Wolves starting forward and defensive stalwart Jaden McDaniels walked into the tunnel near the Minnesota bench and punched what he thought was a fabric wall. He didn't see the brick behind it.

McDaniels immediately clutched at his right fist; his hand was broken.

The Wolves ended up winning. After a subsequent loss to the Lakers, Minnesota and Oklahoma City matched up to determine who would go to the playoffs to face the No. 1-seeded Nuggets.

With McDaniels out, Alexander-Walker drew OKC's toughest matchup -- his cousin Shai Gilgeous-Alexander.

In the first four years of his career, Alexander-Walker had guarded his cousin 27 times in half-court matchups, holding him to 3-of-11 shooting.

Alexander-Walker found out he was starting -- and drawing the assignment -- that morning at shootaround. Eschewing some of his normal game day routine, Alexander-Walker went home and watched three hours of film on his cousin's previous games. He looked for every tell, every move, every play that could happen.

That night, the Wolves dominated, beating the young Thunder 120-95. Gilgeous-Alexander shot 5-of-19 in the loss.

Alexander-Walker next drew the assignment of guarding Nuggets' star Jamal Murray. According to ESPN tracking data, Murray shot 17-of-40 (42.5%) with Alexander-Walker as the main defender and 29-of-53 (54.7%) with any other Wolves player guarding him.

Although Denver won the first-round series 4-1, it was a stifling defensive performance from Alexander-Walker that raised eyebrows throughout the Wolves organization.

"I don't think he was known as a defensive stopper or anything like that coming in, but he really took that pride and took pride in that," Conley says. "And once Jaden went out, it was like, we need somebody to guard Jamal. We need somebody to guard these elite guards. Who can it be?

"He showed up, and he answered the bell."

And Alexander-Walker has continued to do so. Playing in all 82 games for the first time in his career and averaging a career-high 23.4 minutes per game, he held opponents to 41.1% shooting as the contesting defender in 2023-24. Per Second Spectrum, that ranked fourth best among players to contest at least 500 shots.

However, he has struggled to lock down the defending champs this postseason. The Nuggets are currently shooting 49% while he's the primary defender.

"He does not want to be scored on," Wolves assistant coach Jim Boylan tells ESPN. "He's a very competitive person."

AFTER BEING DRAFTED by New Orleans and traded three times, Alexander-Walker finally had a choice of where he wanted to play when he became a free agent last summer.

Remaining in Minnesota would give him the opportunity to do something he'd never done before either: start the season with the same coach he finished the previous year with.

Finch said the team pitched him on both in an effort to bring him back.

"It was so important to re-sign him," Finch said in December. "We saw what he could do to help this team last year down the stretch. He feels really comfortable here. I think we have a greater appreciation for who he is as a player. Now, the defense is way better than we had anticipated, and he understands that that's his ticket to making an impact on the floor."

In July, Alexander-Walker agreed to a two-year, $9 million contract with Minnesota. For the first time in his career, the role he wanted and the one his team needed were in agreement.

"It was a two-way buy-in," Boylan says. "We bought into him, but he bought into us at the same time."

His teammates have bought in too.

"For me, I respect work more than anything," Gobert tells ESPN. "And first of all, I love the way he works every day. And that translates to the court ... every minute that he is on the court. He takes every play serious. He takes every possession serious. ... Everything that he does has a purpose."

Conley says he has seen a "night-and-day difference" from the player he first met to the one he sees now.

Towns, for his part, credits Alexander-Walker for more than just his defense.

"When we really need our team to get disciplined to calm down, he's been the one a lot of times in those actions," Towns says. "So, Keil been tremendous for us. I could be here all day talking about the great things he does for our team.

"We're just super blessed to have him."