The Mariners recalled Swanson from Triple-A Tacoma on Sunday.
Two days after sending him to the minors, Seattle will bring Swanson back to provide the team with an extra arm after Wade LeBlanc (oblique) was placed on the 10-day injured list. Though Swanson worked in relief in his lone appearance with the Mariners this season and will presumably be available out of the bullpen for the next few days, the right-hander could be the top candidate to replace LeBlanc in the rotation the next time a fifth starter is needed Wednesday against the Indians.