Paxton, 28, was 3-0 with a 1.43 ERA in six starts before going on the DL. He threw four innings and 55 pitches in a rehab outing Friday at Double-A Arkansas and said he's "ready to roll," after rejoining the club.
The Mariners are still minus right-handers Felix Hernandez and Hisashi Iwakuma, both sidelined by shoulder issues, as well as lefty Drew Smyly, who has been out since Spring Training with a strained elbow.
Hernandez and Iwakuma both threw a pair of bullpen sessions during the Mariners' last road trip. Hernandez appears closest to returning, as he could go out on a Minor League rehab stint sometime next week and potentially rejoin the team in mid-June, with Iwakuma projected to be a week or so behind.
Smyly has been playing flat-ground catch for the past two weeks and is likely looking at a July return if things continue to progress on schedule.
The Mariners have used 12 starting pitchers over the first two months of the season, the most in the Majors.
Greg Johns has covered the Mariners since 1997, and for MLB.com since 2011. Follow him on Twitter @GregJohnsMLB. This story was not subject to the approval of Major League Baseball or its clubs.