Seattle Mariners relief pitcher Erik Swanson (groin) was placed on the injured list Saturday with a groin strain, and is now expected to miss extended time. Swanson had worked himself into the late-inning mix, with his first career save coming on May 28. Fantasy managers will have to look to Keynan Middleton and Rafael Montero as Seattle's closer options until Kendall Graveman returns from the injured list.