Wittgren announced on Instagram that he underwent surgery Tuesday to remove a bone spur from his elbow.
Wittgren was placed on the disabled list on July 28 after suffering a right elbow strain. He struggled out of the bullpen this year, posting a 4.68 ERA across 42.1 innings. The 26-year-old was used primarily in low-leverage situations, and it seems likely that he'll stay in that role next season.