Last season, the Green Bay Packers' inside linebackers stuggled so badly -- particularly in the running game -- that star pass rusher Clay Matthews had to move off his familiar spot on the edge to take over in the middle of the defense. It was a switch that worked out very well for Green Bay, as Matthews solidified a weakness and the Packers went to the NFC title game.

Over the summer, Matthews learned more and more about the position and warmed up to a move that his brother, Casey, initially said Clay didn't like. The Packers elected not to make any big additions to their inside-linebacker corps in the offseason, even after letting incumbent starter A.J. Hawk leave, so it was expected that Matthews would again spend some time inside in 2015.

That was indeed the case during Green Bay's season opener against the Chicago Bears, with Matthews playing 51 of his 77 snaps at inside linebacker, per Pro Football Focus. He did spend 24 snaps on the edge as well (he covered a slot receiver for two snaps), but that number may not be quite as high the rest of the year.

Though defensive coordinator Dom Capers said Monday it would be a week-to-week decision on how often Matthews shifted outside, Green Bay just may not be able to spare him in the middle. Sam Barrington, Matthews' fellow starter at inside 'backer, suffered an injury that may keep him out for the rest of the season, so the Packers may simply not have enough inside depth for Matthews shift back out to his natural position much more over the remainder of the year. Barrington lasted only 16 snaps on Sunday, with third-year man Nate Palmer taking over the role once he was out. Palmer, a sixth-round pick in the 2013 draft, finished the game with six tackles.

Given the depth Green Bay has at outside linebacker – Julius Peppers, Mike Neal, Nick Perry and Jayrone Elliott all got snaps on Sunday – they can probably get some pressure on the edges without shifting Matthews back outside. Still, the team's best natural pass rusher was already spending more snaps in the middle of the defense than the team likely ever planned on before struggling so badly at the position last season, and now it seems even more likely that he'll spend the majority of his time there.

As it turns out, Barrington's season is officially over, as the Packers announced Tuesday afternoon that they have placed him on injured reserve.

Clay Matthews' position change might become even more permanent. (USATSI)