Swanson is being held back slightly in spring training after feeling some muscle spasms in his right shoulder several weeks ago, Greg Johns of MLB.com reports.

EDGE Analysis

Swanson's spring training is getting off to a slow start, but his lack of usage is likely just a precaution. The right-hander is expected to do some light throwing Saturday, and it wouldn't be surprising to see the Mariners ease him back into normal usage as long as he doesn't experience any setbacks. Swanson made his major-league debut last season, posting a 5.74 ERA and 1.17 WHIP over 58 innings.