NORMAN — Oklahoma’s inconsistency on the ground plagued the offense a year ago, but with new leadership, it may improve in 2026. The Sooners hired Deland McCullough to replace former running backs coach DeMarco Murray in February. McCullough coached the Las Vegas Raiders’ running backs in 2025, and he previously served as a running backs coach at Notre Dame, USC and Indiana. Shortly after McCullough was hired , OU offensive coordinator Ben Arbuckle called him. From one phone conversation, Arbuckle knew that his new coworker was the right man for the job. “We talked for probably an hour, an hour and 15 minutes,” Arbuckle said. “He’s been a great addition to the team.” In 2025, Oklahoma ranked 13th in the SEC in rushing, averaging 118.5 yards per game. Young running backs Tory Blaylock and Xavier Robinson combined for over 900 yards and certainly showed flashes of efficiency, but both of them suffered injuries in the back half of the season that kept the unit from ever truly finding a rhythm.…