Bad news for the St. Louis Rams as they head into their biggest game of the season. Leading tackler, Robert Thomas will be sidelined for four weeks with a torn groin. Thomas has battled the malady all season and even missed one game as a result, but the injury worsened after the Rams win in Cleveland Monday night. Thomas, who has 102 sacks on the season, will be replaced by Jamie Duncan. The Rams are at home against the Seahawks on Sunday and a win will clinch the NFC West title. St. Louis has a two game lead over Seattle.