Cowboys' Tyler Smith headed to IR for thumb surgery

Dallas Cowboys starting left guard Tyler Smith will undergo thumb surgery and is headed to injured reserve, coach Brian Schottenheimer said Monday.

Smith, who has been selected as a Pro Bowler each of the past three seasons, will miss at least the first four games of the season. He has been bothered by the injury for some time and had been hoping to avoid surgery.

T.J. Bass will replace Smith in the starting lineup, Schottenheimer said.