Swanson was recalled by the Mariners on Tuesday, Greg Johns of MLB.com reports.

EDGE Analysis

In seven appearances (six starts) with the major-league club through early May, Swanson recorded an ERA of 8.04, but he had decent command with a 24:5 K:BB. Since then, he's only managed an ERA of 6.98 and a 20:12 K:BB with Triple-A Tacoma. While the right-hander was mostly used as a starter during his previous stint in Seattle, it seems likely that he will pitch primarily in relief for the time being. Outfielder Mac Williamson was designated for assignment in a corresponding move.