Wittgren will compete for a bullpen role with the Marlins in spring training.
He put together a strong major league debut in 2016 thanks to his plus control, but Miami signed Brad Ziegler and Junichi Tazawa in the offseason to bolster their bullpen, and Wittgren's somewhat pedestrian raw stuff leaves him with no guarantees that he'll break camp with a spot on the 25-man roster. He does have plenty of experience as a minor league closer, but Wittgren's role with the Marlins would be in much lower leverage situations if he does hang onto a job.