Controversial all-time great slugger Barry Bonds is going ahead with a case against Major League Baseball alleging that he was colluded against following the 2007 season, Jon Heyman of CBSSports.com reports. Bonds recently had an obstruction of justice conviction overturned, which apparently spurred the effort to proceed against MLB.

Bonds will reportedly assert that the league conspired to keep him from returning to action after the 2007 season. The home run king never found a new team after reaching free agency. 2007 was his age-42 campaign, so he was obviously past his prime, but Bonds still managed to slash an obviously productive .276/.480/.565 with 28 home runs over 477 plate appearances that year for San Francisco. Heyman writes that Bonds’ camp waited until after resolution of his successfully-challenged felony conviction to pursue a collusion claim.

The topic was covered at length here at MLBTR at the time: Bonds’ reputation was in tatters, and there were health questions. Nevertheless, given his unrivaled productivity even at an advanced age — he led the league in OBP in 2007 and five of the six seasons before it — it remained rather remarkable that he did not receive a single offer that offseason (per his agent, Jeff Borris). That has led to various suggestions that Bonds was effectively blacklisted across the league.

As is mandated by the CBA, Bonds’ issue would first be addressed by the grievance process. Bonds appears to be working with the MLBPA on the case. MLB commissioner Rob Manfred, MLBPA head Tony Clark, and Borris all are said to have declined Heyman’s requests for comment.