Chicago Cubs third baseman Kris Bryant has become a mainstay on his club over four MLB seasons, and he's been named Rookie of the Year and NL MVP.

He's also one of the most high-profile examples of service-time manipulation.

Prior to his 2015 rookie season, Bryant was sent to Triple-A to open the year, then recalled near the end of April. He was demoted even after an excellent spring training.

How Bryant was treated then has become a growing trend with top prospects on the cusp of reaching the majors.

"It’s awful," Bryant said, according to Sahadev Sharma of The Athletic. "So awful.

"It’s going to happen this year and it happens every year. I could understand it if you go out and have a rough spring training where you don’t look ready. But there’s certain people who put the time and the effort into the offseason so that they do show up to spring training and they prove that they’re ready to go. I feel like you should be rewarded for that."

A player reaches free agency after six years of service time, and appearing in the majors for 172 days in a season counts as one year, according to MLB's official rules. By pushing back a player's debut so he's in the majors for less than 172 days, a team also delays his free agency for a year, with the front office gaining an extra season of control.

The Toronto Blue Jays, San Diego Padres, and Chicago White Sox are expected to leave their top prospects - Vladimir Guerrero Jr., Fernando Tatis Jr., and Eloy Jimenez, respectively - in the minor leagues when the regular season kicks off, even if those potential young stars perform well in spring training.

After experiencing that process himself, Bryant understands why MLB organizations take advantage of the collective bargaining agreement. Still, he's calling for the loophole to be closed.

"They’re finding a loophole in the system," Bryant said. "It doesn’t make it right. It kind of seems like the easy way out rather than showing someone that we’re going to reward what you’ve done in spring and what you’ve done in the offseason. 'Here you go, you get Opening Day.' That’d be pretty cool."

If a rule change is implemented, it may not be on the table until after the current CBA expires following the 2021 season.