If USC is going to pull an upset of No. 1 ranked Notre Dame this coming Saturday, they’re going to have to do it without injured Matt Barkley. USC announced on Sunday night that the senior quarterback will sit out this weekend’s game with a sprained shoulder. Barkley injured his shoulder in the fourth quarter of the Trojans 38-28 loss to UCLA, USC’s first loss to their cross-city rival since the 2006 season. Redshirt freshman Max Wittek will start in Barkley’s place Saturday. Wittek has thrown just nine passes this season, completing eight of them. It is a disappointing end to a season which started with so much promise for both Barkley and USC. Barkley returned to the school for his senior year after finishing 2011 with a Pac-12 record 39 touchdown passes, and his return was the biggest reason why the Trojans were ranked No. 1 in the preseason. However USC has been one of college football’s most disappointing teams in 2012 limping to a 7-4 record, and Barkley’s play in particular has been especially inconsistent. On the season, Barkley’s numbers are down across the board, with 15 interceptions and a 63 percent completion percentage marring a year where he’s added 36 more touchdowns to his career total. And for the Trojans themselves, Barkley’s injury couldn’t have come at a worse time. On Saturday they welcome their long-time rival, and the only undefeated team left in major college football, the Notre Dame Fighting Irish. The Irish are ranked No. 1 for the first time since 1993 this week, and are looking for their first National Championship since 1988. A win against USC would ensure their spot in the title game. Ironically, it was last year’s 31-17 victory by the Trojans over the Irish which started their run toward their spot as this season’s No. 1 ranked team in the preseason. Following their victory in South Bend last October, USC finished the regular season with four wins in their last five games, and when Barkley returned to school this year it made the Trojans the proverbial favorite to win the 2013 BCS National Championship. However USC’s title hopes are now in the rearview mirror, and at this point all they can do is play spoiler for someone else’s championship run. And they’re going to have to do it without their senior quarterback. Photo via @DuranSports For all his articles, opinions and analysis on college football, please follow Aaron on Twitter @Aaron_Torres.