The Orioles claimed Castillo off waivers from the Mariners on Monday.

Castillo will join his third different team this month after previous stints with the Mets and Mariners. The lefty has posted a 4.38 ERA and 23:11 K:BB over 24.2 frames this season in the majors.

The Orioles recalled Hiraldo from Triple-A Norfolk on Monday.

Hiraldo has posted a 5.65 ERA and 12:6 K:BB over 14.1 frames during his time with the big club this season. He will give the Orioles a fresh bullpen arm.

The Blue Jays designated Borucki for assignment Monday.

Borucki made four scoreless relief appearances during his time with the Blue Jays this month, but it wasn't enough to retain his roster spot. The lefty will likely clear waivers, and if he does, he would have the ability to elect free agency.

Gilbert will serve as the White Sox's opening pitcher in Monday's game against the Orioles.

Gilbert will draw his fourth opener assignment this season after he yielded one run with a 6:2 K:BB over four innings in his first three outings as a starter. Sean Burke is likely to follow Gilbert in a bulk-relief role.

The Rays optioned Acton to Triple-A Durham on Monday, Marc Topkin of the Tampa Bay Times reports.

Acton is clearing out to make room on the roster for Joe Boyle, who is back up from Durham to start Monday's game versus the Blue Jays. The 27-year-old Acton made one appearance during his brief time with the Rays, pitching around a couple walks to throw a scoreless frame.

Whitlock allowed one hit and struck out three over a scoreless inning in Sunday's 6-4 win over the Yankees.

The Yankees had clawed their way back from a 6-0 deficit in the first inning and threatened in the eighth, when Aaron Judge led off with a single. Whitlock then shut it down and earned his 24th hold, getting three consecutive punchouts. It was the ninth consecutive scoreless outing for the reliever, who has allowed nine hits and two walks while striking out 14 over 10 innings during the streak.

Kelly earned the save in Sunday's 7-4 win over the Reds, tossing a perfect ninth inning.

The 33-year-old right-hander converted his first career MLB save with a clean frame, closing out the win. Kelly has been a volatile middle-relief option recently and now carries a 3.09 ERA, 1.26 WHIP and 26:16 K:BB across 35 innings. While Kelly isn't expected to see many more save opportunities as the season closes, Sunday's effort showed he's capable of handling the role when called upon.

Chapman struck out one in a perfect inning to earn the save in Sunday's 6-4 win over the Yankees.

Chapman had given up a run in each of his previous two outings, which is the only time he's been scored on in consecutive appearances all year. He bounced back Sunday to convert his 30th save, 11 of which he's earned since the start of August. The closer's recent missteps haven't done much damage to his overall numbers -- he's still at a 1.26 ERA, 0.68 WHIP and 82:14 K:BB across 57.1 innings this season.

Latz did not factor in the decision during Sunday's extra-inning loss to the Mets. He yielded one run on two hits and four walks while striking out four over 4.2 innings.

Latz worked through four scoreless frames before the Mets finally broke the 0-0 tie in the fifth inning. He hasn't completed six innings in an outing since June 24 as he's bounced around between the rotation, the bullpen and Triple-A Round Rock in recent months. Since moving back into the rotation, Latz has allowed five runs over 20 innings (2.25 ERA) in four appearances. His season ERA is down to 2.85 with a 70:36 K:BB through 79 innings. Latz's role moving forward is unclear, as Tyler Mahle (shoulder) is set to rejoin the Rangers' rotation this week.

Vest allowed a hit and a walk in a scoreless inning while earning a save over the Marlins on Sunday. He struck out one.

Vest had runners on first and second with one out but escaped the jam to close out the 2-0 win. It was his 21st save of the year and first since Aug. 29. He's now delivered 6.1 consecutive scoreless frames, dropping his season ERA from 2.81 to 2.53 in the process. Vest has produced a 67:22 K:BB through 64 innings.