The Vikings lost right tackle Phil Loadholt for the second half Sunday due to a concussion. And they soon paid for it. Loadholt was knocked woozy late in the second quarter against Dallas at AT&T Stadium, a game the Vikings led 10-6 at halftime. But the Cowboys took a 20-10 lead with two touchdowns in the first 3:32 of the second half. The second one came when J'Marcus Webb, Loadholt's replacement, was beaten badly by Dallas defensive end George Selvie.