Santos (lat) fired a scoreless inning during Triple-A Tacoma's win over Salt Lake on Tuesday, allowing a hit and recording a strikeout.

Santos' long-awaited return to game action consisted of 13 pitches, nine which he located for strikes. Per reports from Triple-A Tacoma play-by-play announcer Mike Curto relayed by MLB.com, Santos' fastball was regularly at 97-99 mph during the outing, while his slider clocked in the 87-90 mph range. Santos is slated to make at least a couple of more rehab appearances before activation is considered, and he's expected to be handled with caution once he does return to the big-league roster. "We're going to have to be very guarded on how we use him and kind of build him up," manager Scott Servais said. "It'll be an inning at a time here or there. There will be some days off in between."

McArthur picked up his 15th save of the season in Wednesday's win over the Rays, allowing a hit and no walks while striking out one in 1.2 innings.

McArthur entered in the eighth with two runners on and one out with the Rays already having scored a run in the inning. He was able to navigate through the traffic and then pitched around a leadoff single in the ninth to lock down the save. McArthur has been lights-out of late, throwing eight scoreless innings over his last eight appearances since June 13, and he's converted each of his last four save chances.

Muller (shoulder) started Triple-A Las Vegas' loss to Oklahoma City on Tuesday, allowing two earned runs on two hits and a walk over 2.2 innings. He struck out five.

While he had his share of trouble, Muller encouragingly worked up to 42 pitches during the outing, locating 32 of those offerings for strikes. Per the Associated Press, Muller returned to Oakland on Wednesday, and he and manager Mark Kotsay were slated to discuss how the veteran southpaw felt following the most voluminous of his three rehab appearances before making a decision on whether Muller would be activated at some point during the upcoming weekend series against the Orioles.

The Guardians optioned Morgan to Triple-A Columbus on Thursday.

Morgan holds a 1.98 ERA but just a 10:5 K:BB over 13.2 innings this season and has missed time with a pair of arm issues. David Sandlin (back) has returned from the injured list to take Morgan's spot in the Guardians' bullpen.

The Guardians activated Sandlin (back) from the 15-day injured list Thursday.

Sandlin required just a minimum stay on the IL due to lower-back inflammation. He has a 3.49 ERA in 33 appearances this year and will return to a middle-relief role now that he's healthy.

Kimbrel picked up the save over the Mariners on Wednesday, pitching a perfect ninth inning while striking out two.

Kimbrel entered the contest with a three-run lead in the bottom of the ninth and fanned the first two batters he faced before getting Julio Rodriguez to pop out to first for the final out. The veteran reliever has converted each of his last five save attempts, posting a 9:3 K:BB over that stretch while not allowing any hits. Kimbrel has also recorded two or more strikeouts in four of his last five appearances.

Hendriks (elbow) threw the first of three scheduled bullpen sessions Wednesday, Ian Browne of MLB.com reports.

Hendriks will also throw sessions Friday and Sunday in New York. He was limited to fastballs only, per Red Sox manager Alex Cora, who added that the pitcher is "far off" from a rehab assignment. That remark counters earlier comments from Hendriks, who expressed optimism to be activated around July 30.

Shuster will start Thursday's game against the Guardians, Daryl Van Schouwen of the Chicago Sun-Times reports.

Shuster has appeared in 17 games for the White Sox this season, posting a 3.15 ERA and 1.34 WHIP in 34.1 innings, but Thursday will mark his first start of the season. The 25-year-old southpaw worked almost exclusively as a starter throughout his professional career before joining the White Sox in the offseason, so he should be able to pitch well into Thursday's game before Chicago turns to its bullpen. Shuster may be in line for just a spot start, as the White Sox could get Mike Clevinger (elbow/neck) back from the 15-day injured list next week to complete their rotation.

The Twins transferred Stewart (shoulder) to the 60-day injured list Wednesday.

The right-hander has been on the shelf with shoulder tendinitis since early May, so the move to the 60-day IL won't affect his return timeline. Stewart has progressed to facing live batters this week and could soon begin a rehab assignment.

Garcia (elbow) will throw a bullpen session Wednesday and will need at least one minor-league rehab appearance before being activated, Ben Nicholson-Smith of Sportsnet.ca reports.

If all goes well, Garcia would be sent out for a rehab assignment following Wednesday's bullpen session. While it's unclear exactly how many appearances he'll need in the minors, manager John Schneider indicated Garcia would need more than one outing before rejoining the active roster. Once he's healthy, Garcia could take over closing duties considering Jordan Romano (elbow) will be shut down from throwing for at least six weeks.