Matthews hurt his shoulder in Week 12 (Game 11) and wasn't the same after it. That is almost 1/3 of the season (5.75 games), yet somehow he produced these numbers on a team that didn't quite pressure the passer enough:

Nick Perry led the team in the vital category of pressures with 36. Rounding out the top five were Julius Peppers, 32½; Mike Daniels and Datone Jones, 31½, and Clay Matthews, 28½.
He's been a consummate professional, has been a impact player, played hurt and still affected games. He is coming back for one more year at his current number at least, to see him healthy at least. He might only be good at this point, but he is coming back.