Vikings running backs coach Eric Bieniemy expects more from Adrian Peterson this coming season. Peterson led the NFL in rushing in 2008, just his second season. "I thought he made a tremendous jump from [his rookie season], but also I think he will improve again this year," Bieniemy said. "My main concern with him is just basically getting back to understanding run-game reads. Because, obviously, he had a great year last year, but it could have been so much better. I know for a second-year player to go out and rush for 1,760 yards is a tremendous, tremendous success. "The sky can be the limit."