LONDON - Arsenal defenders William Gallas and Mikael Silvestre are likely to be out of action for three weeks because of injury. Former captain Gallas has a hamstring problem while fellow French international Silvestre has a thigh injury. "I think Gallas and Silvestre will be out for three weeks," manager Arsene Wenger told the club's official website on Thursday. Wenger, however, will have midfielder Denilson and defender Kolo Toure back from injury for Saturday's Premier League home match against Bolton Wanderers. Arsenal are fifth in the table, 10 points behind leaders Liverpool.