Del Rio softens stance on ‘vicious’ hit

Raiders head coach Jack Del Rio amended his stance Monday on the hit that knocked receiver Amari Cooper out of Sunday’s game against the Broncos.

Cooper was hurt in the second quarter of Oakland’s 21-14 win when he reached for a pass and collided with Denver safety Darian Stewart, who lowered his shoulder into the back of Cooper’s head and neck.

Stewart was flagged for unnecessary roughness. Del Rio said Cooper was still in concussion protocol Monday and also “tweaked” his ankle on the incompletion.

After the game, Del Rio described Stewart’s hit as “vicious.” He softened that stance somewhat in his Monday news conference.

“In looking at it and being honest, I think Amari did duck his head as the guy was approaching,” Del Rio said. “That makes it a little harder on the defender. That was probably the one piece that I didn’t have access to prior to that comment.

“Reality is, it’s harder to be on a defensive guy when the offensive guy’s ducking his head. That makes it a little more complicated.”

Denver head coach Vance Joseph had taken exception earlier Monday when asked by reporters about Del Rio’s “vicious” characterization, saying Stewart also had been injured on the play trying to avoid Cooper.

“As a coach, when things happen on the field, you have to go back and watch the tape before you make comments like that,” Joseph told reporters. “It was not a dirty play, in my opinion.”

Cooper had one catch for a 9-yard touchdown before leaving. Matt Kawahara is a San Francisco Chronicle staff writer.