evidence: Steelers Coach Mike Tomlin, who stood on the sideline as his team waited in the tunnel before its game in Chicago, explained that the players stayed inside as a show of team unity. [...] The only Steelers player visible during the anthem was former Army Ranger Alejandro Villanueva, who stood at the tunnel entrance with his hand over his heart. On Monday, Villanueva apologized and said he felt "embarrassed" for showing up the other Pittsburgh players. [...] Clarification: A previous version of this story stated that the Pittsburgh Steelers waited in the locker room during the national anthem. They were in the tunnel near the field.