Denver Broncos defensive end Jason Hunter had surgery on his torn triceps Wednesday and is out for four months.
Coach John Fox also said that right guard Chris Kuper had surgery on his broken left forearm and is out four to six weeks.
Hunter is the team's third defensive lineman to suffer a serious injury at training camp in the last two years. Elvis Dumervil missed the 2010 season with a torn chest muscle and Ty Warren missed last season with a torn triceps.
Hunter had supplanted Robert Ayers as the starter at left end two weeks ago. He was replaced in the base defense by rookie Derek Wolfe, the team's top draft choice who had two sacks at Chicago last week.
Manny Ramirez took Kuper's spot in the lineup.