The Chargers have lost three starting centers this season – Nick Hardwick, Rich Ohrnberger and Doug Legursky. Rookie third-round pick Chris Watt now fills that vacancy for the Chargers. The Broncos have blitzed frequently in the past few games and inexperience at that position could leave the Chargers vulnerable – which was the case against the Patriots when Philip Rivers was sacked four times. "We got a system in place here and we got a great quarterback that can make sure everything is on the right page, everything like that, directing traffic," Chargers Head Coach Mike McCoy said. "It's been the next-man-up mentality. I think the coaching staff has done an outstanding job of adjusting those players. The five centers we've used throughout the year have all stepped up at critical times and have done a nice job, did a good job of directing traffic and making all the calls and everything for us."Watt, a Notre Dame product, had never played center before this season and will start his third NFL game on Sunday. He played guard when the Broncos and Chargers played earlier this season.The shockingly quick and athletic Terrance Knighton will look to take advantage of Watt's youth."You know he's a good player," Knighton said of Watt. "When you're thrown in the fire and you have a quarterback like Philip Rivers, it puts a lot of pressure on you. But the good thing is at center, you can kind of hide. It's not like he's out there on an island at left tackle or anything, but he's a good player, he fights, and he'll bring it to me and I'll be ready."