The Chicago Cubs were arguably the most improved team in baseball this season, and the sensational rookie campaign of third baseman Kris Bryant was a big part of the reason why.

Despite winning the Rookie of the Year award however, Bryant reportedly is not happy with the way that the Cubs handled his ascent to the big leagues.

According to a report by Yahoo's Jeff Passan, Bryant has filed a grievance against the Cubs, saying that the team deliberately took advantage of MLB rules in order to get an extra year of service time before he can apply for unrestricted free agency.

The report also says that Phillies third baseman Maikel Franco has filed a grievance on the same grounds, alleging that the team acted in "bad faith" by manipulating his service clock.

Despite ripping the cover off of the ball during spring training, the Cubs sent Bryant to the minor leagues, a move that riled fans and Bryant's agent Scott Boras.

After a brief stint in Iowa, Bryant was called up in mid-April, and at the end of the season he had accrued 171 service days, one day short of the 172 mark that would have constituted a full year of service time.

Because of this technicality, Bryant will have to wait until after his seventh season with the Cubs to file for free agency, rather than the offseason following his sixth campaign with the team.

While it's unlikely that the Cubs will be punished, the move does set the stage for a fight over the issue when the new collective bargaining agreement is negotiated, according to Passan.