GREEN BAY, Wis. -- Packers linebacker Clay Matthews underwent another surgery this week on his broken right thumb after re-injuring it in Sunday's loss to the Pittsburgh Steelers.

"They have not given me a timeline on Clay," Packers coach Mike McCarthy said Friday about Matthews' return.

It was the second time this season that Matthews injured that thumb. The first time was against the Detroit Lions on Oct. 6, when he broke it while sacking quarterback Matthew Stafford.