Broncos defensive tackle Gerard Warren did not make the trip to San Francisco on Sunday as the team attempts to trade him. Two NFL sources confirmed Warren, who started the past two seasons for the Broncos, is on the trading block. The Broncos would pick up part of his salary, which was trimmed during the offseason. Warren, who had 51 tackles and 2 1/2 sacks last season, became expendable because he is not considered a good fit for Jim Bates' system where tackles are to primarily leverage their position and hold the point. Warren is a tackle who can penetrate the backfield. Should Warren be traded, Jimmy Kennedy would start alongside Sam Adams at defensive tackle. Veteran Alvin McKinley and rookie Marcus Thomas would also move up the depth chart.