GREEN BAY -

The Green Bay Packers know what life is like without Clay Matthews, and they're bracing themselves again for being without their four-time Pro Bowl outside linebacker for an extended time after Matthews broke his right thumb during Sunday's 22-9 victory over the Detroit Lions at Lambeau Field.

Packers coach Mike McCarthy said in his usual day-after-the-game news conference Monday afternoon that Matthews was at a doctor's appointment being examined and that he was unsure how long his star defensive player would be sidelined.

ESPN'S Adam Schefter is reporting Matthews could miss a month. FOX Sports' Jay Glazer says Matthews had successful surgery today.

Matthews injured his thumb on the final play of the third quarter, when he came unblocked and sacked Lions quarterback Matthew Stafford for a 12-yard loss.