Green Bay Packers star linebacker Clay Matthews is expected to miss one month with a broken thumb, a league source told Adam Schefter of ESPN.
Matthews, who suffered the injury in Sunday's victory over the Detroit Lions, is undergoing more testing Monday, according to the source.
Packers coach Mike McCarthy would not disclose any information regarding Matthews' injury but said he hopes the four-time Pro Bowler will not miss the rest of the season.
"I'm hopeful it's not season-ending," McCarthy said Monday. "I think we're all hopeful, but you have to get all the opinions and make sure you always do right by the player."