Faedo (hip) will throw a bullpen session Thursday, Chris McCosky of The Detroit News reports.

Faedo looks set to throw off a mound for the first time since he landed on the 15-day injured list last week with inflammation in his surgically-repaired right hip. He looks to be closing in on a rehab assignment and shouldn't need too many appearances before being activated since he hasn't missed extensive time.

Coulombe said Wednesday that he underwent an MRI on his left elbow but remains optimistic that he'll avoid an extended stay on the 15-day injured list, Jacob Calvin Meyer of The Baltimore Sun reports.

Coulombe -- who was placed on the IL on Tuesday with left elbow inflammation -- had Tommy John surgery back in 2011 but noted that the pain he's currently experiencing is in a different area of the elbow. The results of his MRI aren't yet known, but the reliever seems confident that he'll be back in the Baltimore bullpen in relatively short order.

The Mariners recalled de Geus from Triple-A Tacoma on Wednesday.

De Geus made four appearances out of the Seattle bullpen earlier this season, allowing one run over 3.1 innings. He'll likely be used mostly in low-leverage situations while he's up with the Mariners.

The Mariners optioned Diaz to Triple-A Tacoma on Wednesday.

Diaz made a spot start in Tuesday's 4-3 loss to the White Sox in place of the injured Bryan Woo (arm), allowing three runs over 5.1 innings in a no-decision. Woo's status remains in limbo, and Diaz could be considered for a call-up if Woo ends up landing on the injured list before his next turn through the rotation comes up.

The Athletics activated Erceg (forearm) from the 15-day injured list Wednesday.

Erceg spent the minimum amount of time on the IL and was able to skip a rehab assignment prior to being activated. He's been terrific in relief for Oakland this season, collecting a 2.86 ERA and 27:8 K:BB across 22 innings as the primary setup man ahead of closer Mason Miller.

Stewart (shoulder) threw five pitches off the mound Wednesday, Do-Hyoung Park of MLB.com reports.

Stewart threw off the bump for the first time since he went down with right shoulder tendinitis more than a month ago. He'll need to continue going through a ramp-up progression and will likely require at least a rehab appearance or two before returning from the 15-day injured list and slotting back into a setup role for the Twins.

Alexander (0-1) took the loss against the Padres on Tuesday, allowing an earned run on one hit and one walk over two-thirds of an inning.

Unfortunately for Alexander, the one hit he allowed was a walk-off solo home run to Kyle Higashioka, saddling the veteran southpaw with his first loss of the season. Alexander has now allowed an earned run in each of his last two appearances after generating four consecutive scoreless efforts of an inning apiece, but he's still carrying an acceptable 4.00 ERA and stellar 0.67 WHIP across the nine innings covering his 10 appearances.

Thornton (2-1) got the win against the White Sox on Tuesday, firing 1.2 scoreless innings while recording two strikeouts.

Thornton was rewarded for his pristine work -- he cruised through his six-out outing on 11 pitches, 10 of which found the strike zone -- when Cal Raleigh drove home the tying and go-ahead runs in the home half of the seventh inning after the reliever had thrown his last pitch. Thornton has bounced back from a rare stumble against the Angels on May 31 (three runs allowed over two-thirds of an inning) to produce scoreless efforts in three of his subsequent four appearances, a span in which he's recorded a pair of holds in addition to Tuesday's win.

Abreu didn't allow a baserunner and struck out one across a scoreless eighth inning to earn the hold Tuesday against the Giants.

Abreu turned in his fifth consecutive scoreless appearance and has earned four holds in that span. He has a team-high 15 holds this season and is also ranked inside the top five in the league with that mark. Overall, Abreu has an effective 2.88 ERA, though he has issued 20 free passes across 34.1 innings.

The Twins designated Castillo for assignment Wednesday, Do-Hyoung Park of MLB.com reports.

The Twins needed to free up a spot on their 40-man roster for the addition of right-hander Jay Jackson to the bullpen. Castillo had just been sent down to Triple-A St. Paul on Tuesday following a brief stint with the big club in which he allowed two runs with a 3:7 K:BB over seven innings. If Castillo clears waivers, he will have the ability to elect free agency if he chooses to do so.