On Opening Day this season, six of the top 25 prospects in baseball took the field with their respective MLB teams. But years before Julio Rodriguez, Spencer Torkelson, Bobby Witt Jr. Hunter Greene and others in a stellar rookie class of 2022 broke camp as major leaguers, there was Kris Bryant.

Bryant, who just played against his former team on the April 17 anniversary of his MLB debut for the Chicago Cubs seven years ago, has been the poster player for the service-time manipulation that has long kept top prospects in the minors rather than allowing them to start the season with their major league teams.

Throughout the recent CBA negotiations, the union pointed to Bryant's case as the example of a system that didn't work. One of the top priorities of the players' association this year was to make changes that would benefit future top young stars.

Bryant was drafted No. 2 overall by the Cubs out of the University of San Diego in 2013 and quickly won minor league player of the year honors the following season. In the spring of 2015, he tore up the Cactus League with a .425 batting average while leading the majors with nine spring training home runs. But instead of heading to Chicago, he was sent to Triple-A Iowa as a 23-year-old prospect -- to "get in a good rhythm defensively," then-Cubs president Theo Epstein said at the time.

Bryant was called up less than two weeks later -- a date that left him with 171 days of service at the end of the year. That fell short of the requirement for a full season by one day -- which meant his free agency was delayed by a full season.

If @KrisBryant_23 doesn't make the big league team out of camp, then that's a joke! I see you doin your thing brotha! #VegasMade #TheTruth

— Bryce Harper (@bryceharper3) March 14, 2015

He went on to win NL Rookie of the Year, making the prorated minimum of $570,500. The next season he won National League MVP as the Cubs won the World Series. He made $652,000.

Following his rookie season, Bryant and his representatives filed a grievance with the league, arguing that Bryant's nearly full (and incredibly productive) season in 2015 should count toward his six years of team control. After losing that case via an arbitrator's ruling in January 2020, Bryant became a free agent this past offseason and ultimately signed a seven-year, $182 million deal with the Rockies.

Bryant's losing his grievance was a rallying point for many players during the lockout.

"When we went to a hearing, I told Kris there was no way an arbitrator was going to legislate new rules," said Scott Boras, Bryant's agent. "This step would create a basis for overcoming the commissioner's office argument that if there's true service-time manipulation, a grievance would remedy any wrongdoing.

"The 'Bryant Rule' was created on the basis of the fact that no arbitrator would in fact legislate new rules as evidenced by the clear, factual premise that clearly illustrated service-time manipulation was happening. It was boldly utilized saying there is no rule that prevents it and was so stated in the hearing testimony."

And so during this past winter's CBA negotiations, the union pushed back hard on such instances of service-time manipulation. The league and union agreed to several changes moving forward:

• No matter when a player comes up from the minors, he'll be awarded a full year of service if he finishes first or second in Rookie of the Year voting.

• A new system put in place now rewards teams with extra draft picks if they promote their top prospects on Opening Day. A player who receives a full year of service time and finishes in the top three in Rookie of the Year voting or top five in MVP/Cy Young voting will earn his team an extra draft pick coming after the first round.

• A new pre-arbitration bonus pool allows the best players in a class to boost their pay significantly through on-field performance while still in the early arbitration years of their contract. The top 100 players via a WAR-based formula and the end-of-year award winners will split up $50 million annually.

While it all came too late to help Kris Bryant, the next Kris Bryant will benefit greatly.

"It's nice to see some changes in that area," Bryant told ESPN this spring. "It feels good that guys are going to be more rewarded for what they do on the field. If I paved the way, that's great."

Perhaps no 2022 rookie's path mirrors Bryant's more than that of Detroit Tigers first baseman Spencer Torkelson. The No. 1 overall pick by the Tigers in the 2020 MLB draft after a collegiate career spent rewriting the record books at Arizona State, Torkelson dominated the minor leagues last season, using his powerful swing to belt 30 home runs and drive in 91 runs in 121 games.

As Bryant was with the Cubs in 2015, Torkelson is the face of a wave of young players who have the Tigers excited about years of contention on the horizon. But unlike Bryant, Torkelson made his major league debut on Opening Day in Detroit earlier this month instead of spending weeks in the minor leagues for more seasoning.

The 22-year-old Torkelson was well aware of Bryant's plight -- as well as the fight the union put up this offseason.

"The younger guys appreciate the veterans putting in the work, not only for them, but fighting for the younger generation," Torkelson said. "They were us at some point, and they wanted us to get a fair chance as well."

Team executives have been caught in the middle of that fight for years, weighing the immediate on-field advantage of having their best players for 162 games with the long-term payoff of a system that rewarded delaying debuts.

"As an industry we should not be stopping these guys from being stars," Mariners general manager Jerry Dipoto said. "It's not lost on me, with this new CBA, that we saw more of it [top prospects making teams] this year. It could just be because we're dealing with an extraordinary group of players or it could be because those two planets meshed."

Dipoto insists Julio Rodriguez, the Mariners' top prospect who also opened the season on Seattle's roster, made the team because of his play -- but also because Seattle had already put him on its 40-man roster, which it did after last season to protect him from the Rule 5 draft. That's a distinction the longtime executive stressed in comparing Rodriguez's situation to Bryant's.

"The most overplayed thing we hear about is service time, service time, service time," Dipoto said. "It's the options that are the issue. Julio is a 40-man player. The day he goes to the minor leagues, you're already burning an option. Once you're on the 40-man, there is no true decision to be made."

Teams get only three seasons when they can option a player to the minors, and another addition to the new CBA is a rule limiting teams to optioning a single player five times in a season.

This philosophy on Rodriguez's position on the roster is a change from how the Mariners treated outfield prospect Jarred Kelenic, who was at the forefront of the conversation on service-time manipulation last year. After Kelenic started the 2021 season in the minor leagues, public comments by then-team president Kevin Mather made it clear it was only to extend team control after Kelenic turned down an extension offer. Kelenic, who was not in danger of the Rule 5 draft, was not added to the 40-man roster until he made his major league debut last May.

While the changes appear to be serving their purpose thus far, it remains to be seen if any unintended consequences will come from the new additions to the CBA. The biggest potential one would be if teams start holding players back even longer to ensure they won't have enough time in the big leagues to finish at the top in Rookie of the Year voting. A team could get a half season of great production and still keep a player for that extra year on the back end, but would lose out on gaining draft picks.

"I'm interested to see how this plays out," Bryant said. "Hopefully it doesn't lead to worse behavior where they're hiding a guy down for four months just to deny him, but all that is yet to be seen."

Even with six of this year's top prospects debuting on Opening Day, there was one notable exception: Pirates shortstop Oneil Cruz, who ranked No. 13 on Kiley McDaniel's preseason Top 100. The 6-foot-7 infielder made headlines with his tape-measure home runs during spring training, but he began the season in Triple-A, leaving one fan base waiting to see its brightest young star in the majors.

But there is no denying the progress the union made in terms of everyday dollars for the best young players already in the majors.

Bryant points to Corbin Burnes, the NL Cy Young Award winner in 2021, as the perfect example. "Burnes was worth five times what the Brewers paid him last season," Bryant said.

In his fourth year with the Brewers, Burnes compiled an 11-5 record, 2.43 ERA and led all pitchers with a 7.5 FanGraphs WAR. But because he is still in pre-arbitration, he made just $608,000 in salary. After the CBA changes, if the Brewers ace were to take home the award again in 2022, he'd get a bonus -- something Bryant didn't receive after his back-to-back award-winning seasons in 2015 and 2016.

Bryant knew that winning his service-time grievance was a long shot even when he filed it, but change needed a face and his case brought an issue for young players to the forefront.

"Going through all that, I knew it wasn't necessarily for me," Bryant said. "All that going my way was very slim. I took it upon myself thinking, 'I need to do this for the people that come after me.'"