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.

Triple-A Rochester reinstated Eder (undisclosed) from its 7-day injured list Wednesday and assigned him to Double-A Harrisburg.

Eder made his organizational debut later that day, striking out a batter and allowing one hit and no walks over two scoreless innings. The 26-year-old lefty occupies a spot on the Nationals' 40-man roster, but he may not get a look with the big club over the final two weeks of the season unless the Washington pitching staff is decimated by injuries.

Adam is expected to face a recovery timeline of 6-to-9 months after he underwent surgery Sept. 3 to address a ruptured left quadriceps tendon, MLB.com reports.

Adam sustained the season-ending injury during his relief appearance against the Orioles on Sept. 1, when he felt the quad pop while he tried to make a defensive play. Though his surgery seems to have gone off without a hitch, Adam's estimated recovery timeline suggests that he won't be ready to go for the start of spring training in February, and his availability for Opening Day could also be in question. The 34-year-old right-hander, who is under club control through 2026, was a first-time All-Star this season and accrued a 1.93 ERA, 1.15 WHIP and 70:25 K:BB to go with eight wins and 30 holds over 65.1 innings before rupturing his quad.

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.

Atlanta announced Saturday that Bummer (shoulder) has resumed a throwing program, but the left-hander hasn't yet been cleared for bullpen sessions, MLB.com reports.

Bummer has been on the injured list since Aug. 24 due to left shoulder inflammation, and while he hasn't been shut down for the season, he's running out of time to complete his throwing program and rejoin the Atlanta bullpen. Prior to being shut down, Bummer recorded three wins and two holds while submitting a 3.81, 1.25 WHIP and 51:17 K:BB in 54.1 innings over 42 appearances for Atlanta.

Rodriguez is scheduled to undergo Tommy John surgery on his right elbow during the final week of September, MLB.com reports.

Rodriguez has known for a few weeks that he would need Tommy John surgery after he was placed on the injured list Aug. 26, but he'll end up delaying the procedure for nearly a month, presumably because he was waiting for the inflammation in his elbow to subside. Assuming his surgery goes off without any complications, Rodriguez will face a 12-to-18-month recovery, which will keep him out for the entire 2026 campaign. Before suffering the injury, Rodriguez earned his first All-Star nod after submitting a 1.78 ERA, 0.89 WHIP and 67:11 K:BB while collecting three wins, four saves and 13 holds over 50.2 innings this season.

Miller (elbow) completed a bullpen session at Oracle Park on Saturday, MLB.com reports.

Miller has been on the shelf since July 5 due to a left elbow sprain and incurred a setback in mid-August after making four rehab appearances for Triple-A Sacramento, but he's been able to resume his throwing program following a brief shutdown period. The southpaw still appears to have a chance at returning from the 60-day injured list before the end of the regular season, but due to the extensive time he's missed, the Giants may not be eager to deploy him in high-leverage spots right away while the team fights for a wild-card spot.