If the Washington Redskins manage to turn around their season from here they will be able to look back on the play rookie cornerback David Amerson made in Oakland in their most recent game as the springboard. Amerson’s interception and touchdown sprint got the Redskins back in contention in a game they trailed by 14 points putting them on their way to their first victory of the season after an 0-3 start. Now as they return from the bye week and prepare to play Sunday night at Dallas the Redskins hope Amerson continues to add polish and consistency to his game so he develops into a steady reliable cornerback as well as a big-play contributor. “I think he’s much improved” defensive coordinator Jim Haslett said Thursday at Redskins Park. “I think he’s much improved from the first two games. I think he’s got more confidence in what he’s doing. He made the nice play against the Raiders for the touchdown. But he has that ability to do that all the time. Being a young guy . . . I think his future is bright ahead of him.” The Redskins used the NFL draft in April to try to remake their secondary after ranking 30th in the NFL against the pass last season. Amerson was a second-round pick out of North Carolina State. The team also selected two safeties taking Fresno State’s Phillip Thomas in the fourth round and Georgia’s Bacarri Rambo in the sixth. It appears at this point that only Amerson will make a significant impact as a rookie. Thomas is on the injured reserve list after suffering a Lisfranc injury during the preseason. Rambo opened the season as a starter but quickly lost his starting job and now is attempting to work his way back into the playing rotation. But Amerson has stepped right in alongside cornerbacks DeAngelo Hall and Josh Wilson. He has had his rookie-year learning experiences and secondary coach Raheem Morris said last week during that Amerson’s performance so far has been a mixed bag.