It was announced by Mike McCarthy at his Monday press conference that Barnett would need surgery, and a new defensive player caller would be needed for the Packers.
Barnett isn't having the greatest of seasons this year, but he still leads the team in tackles with 49. The one area of his game that is really struggling is the fact that he has not recorded a single sack or interception all year.
Even with his numbers being thin, Barnett was the leader on defense for the 4-5 Packers, and it's always tough to lose one of your leaders.
Now, the big question is, who will have the radio in their helmet on defense for Green Bay?
There are four possible players who could get that lime green sticker on their helmet; Brandon Chillar, A.J. Hawk, Brady Poppinga or Desmond Bishop.
The frontrunner seems to be Barnett's replacement, Desmond Bishop, as to not disrupt Hawk, Poppinga or Chillar at the outside linebackers.
Bishop entered the Viking game when Barnett left early and got several chances to prove himself worthy.
He was quickly burned by Chester Taylor on a gorgeous cutback move. Later, Bishop committed a stupid personal foul penalty with a late hit out of bounds on a punt return by the Vikings.
Eventually Bishop got it together and made some good plays on defense to earn a chance to be in the middle for the rest of the year.
The Packers defense has been sketchy against the run at best, and has been able to shut down the pass all year with a very solid secondary.
With a new defensive play caller, can the Packers shore up that run defense, and try to salvage the season before their playoff hopes vanish?