Josh McCown has torn ligament

Tampa Bay Buccaneers quarterback Josh McCown, who will be watching from the sidelines as Mike Glennon gets the start Sunday at Pittsburgh, has a torn ligament in his thumb, a source told ESPN NFL Insider Adam Schefter.

McCown will try throwing Monday to see if the pain is manageable. If he is unable to throw, and decides to undergo surgery, he would miss at least six weeks, the source said.

McCown, who had been trying to deal with the injury through therapy, said earlier this week that he was trying to avoid surgery.

"We take this thing day by day and, obviously, if it was that pressing of a need, I would have probably already had that done,'' McCown said Thursday. "We're very optimistic with being able to get healthy and move forward.''

McCown also talked Thursday about being almost like a coach to Glennon in the short term.

"I just believe that every person in the organization has to bring value to your job,'' McCown said. "You have to try and find a way that you can help us every week win football games. It's been as tough a three weeks for me as I've had in my career just from a disappointment standpoint. But it's not my makeup to sit and sulk. We have 13 games left. There's a lot of football left to play.''

ESPN.com's Pat Yasinskas contributed to this report.