In Joe Krivak's offense, running backs do a lot of shifting. Now, because of some nagging injuries and a lack of depth, they are shifting positions.

Mike Anderson, who made his first start at tailback in Saturday's 14-0 victory over Wake Forest, will return to a backup role this week against Duke, although he still will play quite a bit. Part of the reason for the change is that Bren Lowery, whom Anderson replaced, ran well Saturday. Another factor is that Anderson also backs up fullback Dennis Spinelli.

"Those three are our three backs," Krivak said yesterday, adding that freshman Mike Beasley might work at tailback to give Anderson and Lowery rests.

Spinelli has started every game at fullback, but he left last week's game three times because of several minor injuries. "He needs more hands to grab all the places that hurt," running back coach Tony Whittlesey said.

Carl Morton had been the backup fullback going into the Miami game. But Morton, although a good runner and receiver, has not been as proficient a blocker, a critical deficiency for any fullback. So, despite being 5-foot-9 and 185 pounds, Anderson is the backup.

Despite starting at tailback Saturday and gaining 53 yards on 16 carries, he had more plays at fullback, with Lowery working at tailback and gaining a team high 83 yards on 19 carries.

"Bren and I are on the field together and we can each do a lot," Anderson said. "With Spinelli injured, we have to make adjustments."

Anderson, who has leukemia, missed Monday's practice because he said his white-blood count had risen slightly and he felt a bit weak. He said yesterday he felt fine and worked out with the rest of the team.

"Hopefully, that's all it is," Krivak said. "We can't afford to lose Mike Anderson. He's the best back we've got because he does so many things."

Wide receiver Azizuddin Abdur-Ra'oof, who was hobbled a bit Monday with a thigh bruise, also worked out yesterday. . . Krivak said defensive left tackle John Sorna would not be able to start against Duke. Mark Agent, who has been working at backup center, and Ben Jefferson, worked with the first group yesterday.