Arizona Cardinals outside linebacker O'Brien Schofield underwent an MRI on Monday on the injured left ankle that caused him to exit Sunday's 31-17 loss to the Green Bay Packers. Unfortunately, he got news that he would miss the remainder of the 2012 season.

I'm out for the season. I'm sorry Cardinal fans. But I will be back and stronger then ever. This yr was just a preview of why is to Come.

— O'Brien (@Ob_Scho) November 6, 2012

The injury is a major blow to the team's already depleted defense as it heads into the Week 10 bye. The Cardinals will now likely turn to Quentin Groves, who will have to fill the void left by Schofield.

Schofield started all nine of the Cardinals' games this season and had four sacks. It was the former Wisconsin Badgers' first year as a starter on a defense that looked strong in the early going. Groves is in his fourth year and has yet to start in 2012. He has two sacks this season in limited action.

Arizona has a 4-5 record and is seventh in the NFL in total defense, holding opponents to an average of 19.2 points per game. They've struggled to stop the run, however, and are ranked 23rd in rushing yards allowed per game with 126.1.