Sunday’s AFC West showdown is critical for the Broncos in plenty of ways, and now it looks as if the Broncos will go at it with a backup QB. Chris Simms was taking snaps with the Broncos’ starters again Thursday.

That makes it increasingly likely that Simms will start against San Diego on Sunday in place of Kyle Orton, who sprained his left ankle last week against Washington.

Coach Josh McDaniels said Orton was feeling better, but Simms was the one under center during the portion of practice open to the media Thursday.

Simms hasn’t started a game since September 2006, when he played for the Tampa Bay Buccaneers and was battered so badly by the Carolina Panthers that he needed emergency surgery to remove his spleen.