"There's something in there," Blue Jays general manager J.P. Ricciardi said on Thursday. "He might have some damage in there that requires surgery, but he thinks he can fight through it. That's really his call."
Maroth, 31, signed a Minor League contract with the Blue Jays in December with the hope of competing for a spot in the club's starting rotation. Maroth, who is trying to return from a left shoulder injury and hasn't appeared in the big leagues in two seasons, is one of at least eight pitchers in the mix for a starting job with Toronto.
Maroth spent much of the day on Thursday in the trainer's room, where he met briefly with Blue Jays manager Cito Gaston. According to Gaston, Maroth isn't sure how he injured his knee, which "locked up" on him early Wednesday. Maroth's injury is believed to be a torn meniscus -- an injury that could require four to six weeks of recovery time after surgery.
The setback puts Maroth well behind in the race for a rotation spot.
"It's not good," Gaston said. "You can't do a thing about it. It's another body, we've got to move on and see if we can find a different one -- somebody else. You feel bad for him, that's for sure. He's not done yet, but it's one of those things where you do need to be doing something in order to certainly make this team."
Maroth underwent a procedure last May 15 to repair some fraying of the labrum in his throwing shoulder, ending his season prematurely. Prior to his surgery, Maroth had gone 0-2 with a 12.91 ERA in 7 2/3 innings for Triple-A Omaha, an affiliate of the Kansas City Royals.
The last time Maroth suited up in the Majors was in 2007, when the left-hander had stints with the Tigers and Cardinals. That year, Maroth finished 5-7 with a 6.89 ERA, bringing his career record to 50-67 with a 5.05 ERA in 161 games.
In six big-league seasons, Maroth has logged more than 200 innings twice, with his best season occurring in 2005. That year, just two seasons removed from losing 21 games, the lefty won a career-high 14 for Detroit and posted a 4.74 ERA in 34 starts.
Roster moves: The Blue Jays outrighted pitchers Brian Burres and Reid Santos to Triple-A Las Vegas, vacating two spots on the club's 40-man roster. Burres -- claimed off waivers from Baltimore on Feb. 4 -- has been mentioned as a candidate for a rotation job.
Jordan Bastian is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.