For three days last season, the Phillies chose to play without a regular third baseman.

Cody Asche was demoted to triple-A, where he would learn to play left field. Cesar Hernandez, who had spent most of the first month as a middle infielder, was tasked with filling the void. Andres Blanco, a reserve infielder, chipped in, too.

But Hernandez and Blanco were not their lone options. Maikel Franco, ranked before the season as the team's third-best prospect, was batting .346 at triple-A Lehigh Valley on May 12 when the Phillies moved Asche to the IronPigs. Franco was ready for the majors. But the Phillies knew that keeping him in the minors until May 15 would keep Franco from free agency for an extra year.

The Phillies did just that. And now Franco has filed a grievance against the Phillies. Franco, according to the report, alleges that the Phillies manipulated his service time in order to delay free agency. Yahoo Sports, which first reported on the grievance, said Franco is joined by rookie of the year Kris Bryant, who filed a grievance after the Cubs started his season in the minor leagues despite Bryant's major-league leading nine homers in spring training.

"The important thing is to maintain positive relationships with the organization, especially for a player like Franco, who represents building for the future of an organization," said Franco's agent, Ryan Royster. "He's an essential piece for an organization. You have to keep all of those things in mind and do everything possible when working on behalf of a client and their best interest."

The Phillies declined to comment. It is worth noting that the decision to hold Franco in the minors was made before the arrival of team president Andy MacPhail and general manager Matt Klentak.

Franco spent the end of 2014 with the big-league club, totaling 27 days of major-league service time. A year of service time is equal to roughly 172 days. Keeping Franco in the minors until May 15 guaranteed that he would not reach that number before the end of the 2015 season. Therefore, he will reach his first service year in 2016 and become a free agent in 2022 instead of 2021.

"The people of Philadelphia have to know that that is home to him now. He's happy there," Royster said. "This has nothing to do with his appreciation for the organization or most importantly for the fans. Franco is a Phillie. He loves the city of Philadelphia and the fans he gets to represent every day."

The Phillies reasoning for keeping Franco in the minors when they demoted Asche could be that they needed to open a roster spot for pitcher Sean O'Sullivan, who was activated off the disabled list to start May 12 against Pittsburgh. But the Phillies could have trimmed their eight-man bullpen to make room for O'Sullivan and then switch Asche for Franco.

According to the report, Franco's grievance could be heard by an arbitration panel or both parties could come to a resolution before then. Keeping Franco from being a free agent denies him a year of reaping the rewards that should come with the prime of his career. The grievance will also serve as a test case for the Major League Baseball Players Association, which is negotiating a new collective bargaining agreement and could be seeking to rewrite the service time rules.

"The players have a great union and I think they want to see the best for their players," said Royster. "I can't predict the outcome of this situation, but I think what the union is doing heading toward a new CBA shows that they are dedicated to the players."

@matt_breen