LSU defensive end Princeton Malbrue was escorted to the locker room by the Tigers’ training staff in the second quarter of the team’s season opener against USC in Las Vegas on Sunday. Not returning to the game with a knee injury that head coach Brian Kelly recently revealed looks severe for the Louisiana native. “The only disappointing news is Princeton Malbrue looks to have a serious knee injury,” Kelly said on Tuesday. “We’re going to do a little bit more imaging on that today, but the the initial imaging was not good.” CLICK HERE to go to PrizePicks and use code ON3 to receive a guaranteed …