Packers linebacker Clay Matthews hurt his thumb in Sunday's win over the Lions. (Tom Lynn/Getty Images)
Pro Bowl linebacker Clay Matthews is expected to miss up to a month with a broken thumb, ESPN.com's Adam Schefter reported Monday.
Matthews underwent successful surgery on the thumb Monday night, according to Fox Sports' Jay Glazer.
Matthews appeared to suffer the injury in the third quarter of Green Bay's 22-9 victory over the Detroit Lions when he sacked Lions quarterback Matthew Stafford.
"I'm hopeful it's not season-ending," Packers head coach Mike McCarthy said. "I think we're all hopeful, but you have to get all the opinions and make sure you always do right by the player."
The Packers still can place one player on their injured reserve/designated-for-return list. Such a move would provide flexibility to sign another player to take Matthews' roster spot, but Matthews would have to sit for at least six weeks.
Matthews has 18 tackles, three sacks and two forced fumbles this season.