Major League Baseball is investigating a dispute between the Toronto Blue Jays and Steve Tolleson after general manager Alex Anthopoulos accused the infielder of quitting on the team earlier this season.

The dispute, according to John Lott of the National Post, stems from whether Tolleson was indeed injured when the Blue Jays designated him for assignment July 1 - the same day his minor-league rehab assignment expired.

Tolleson, who played two games for Triple-A Buffalo before the rehab assignment ended, insists he's been injured ever since the Blue Jays placed him on the disabled list on May 27.

"If I was able to play," Tolleson told Lott, "I would be playing."

Anthopoulos, however, believes the 31-year-old was healthy enough to play by the time his rehab was over. Under terms of the collective bargaining agreement, an injured player can't be designated for assignment.

"Steve Tolleson just decided he didn't want to play anymore," Anthopoulos told reporters Wednesday, before adding on Friday: "There is a potential dispute over Steve Tolleson's assignment and I can't comment further on the matter at this time."

Tolleson says he's been slowed by groin, hip, and hamstring injuries this season. He told Lott that the players union and commissioner's office are "sharing facts" in an effort to find a resolution.

"I have a wife and two kids, and over the last three months I haven't had an opportunity to be with them because of my injuries, going from doctor to doctor, from Florida to Buffalo, and traveling with the Buffalo team, trying to focus on getting healthy," he told the Post. "If I would have wanted to quit, I would have gone home to be with my family."