Denver moved center J.D. Walton to the active roster on Tuesday and placed John Moffitt on the reserve/left squad list.
A catastrophic leg injury ended Walton's 2012 season early, and an infection found in the area in June landed him on the PUP list.
With Manny Ramirez excelling at center, Walton returns to a backup role.
However, Andrew Mason says Walton's lack of positional versatility means a potential injury to one of the starting guards could result in Ramirez moving over, and Walton taking the pivot.
Seattle made Moffitt a third-round pick out of Wisconsin in 2011; the Broncos acquired him in August in exchange for Sealver Siliga, who has since moved on to New England's practice squad.