Royals Select Aaron Bummer

The Royals announced this afternoon that they’ve placed right-hander Luinder Avila on the 15-day injured list with right forearm tightness. They’ve also selected the contract of left-hander Aaron Bummer from Triple-A Omaha. Meanwhile, outfielder Kyle Isbel has concluded his rehab assignment, and the team has reinstated him from the injured list. Avila’s IL placement and yesterday’s Lane Thomas/Bailey Falter trade left open spots on the active and 40-man rosters, which are now taken by Bummer and Isbel.

Bummer joined the Royals on a minor league deal a couple of weeks ago after spending a month and a half with the Cubs’ top affiliate. He’d struggled to a 7.63 ERA in 15 1/3 innings with the Braves earlier this season, though he’s done better in a small sample at Triple-A. He is playing out the last season of the two-year, $13MM pact he signed with Atlanta entering the 2025 season. As was the case when the Cubs signed him, the Royals are only paying Bummer the prorated league minimum, with the remainder of his salary covered by the Braves.

Recent struggles aside, Bummer has a track record as an effective relief arm and ground ball specialist. Since the start of 2023, his 56.9% ground ball rate is better than all but 11 qualified relievers. Bummer does have a 5.01 ERA in 183 1/3 innings in that span, though that’s inflated by a 6.79 ERA in 2023, which was accompanied by expected figures about three runs lower and an uncommonly low 55.4% strand rate. From 2024-25, his ERA was a more palatable 3.69 in 109 2/3 innings.

That’s not to take away from Bummer’s struggles this year. His sinker and four-seam velocity are both at career lows, and he’s already surrendered six home runs after allowing just three in 54 1/3 innings last year. The Royals are surely aware of those struggles, but given that they just sold on Thomas and are ten games out of a Wild Card spot, they can afford to let Bummer figure it out over the next two months.

The same may be true of Avila when he eventually returns. The 24-year-old started the season in the Royals’ bullpen before transitioning to the rotation in June. In 11 starts since June 1st, he has a 5.73 ERA in 48 2/3 innings, along with below-average strikeout and walk numbers. In contrast, Avila’s above-average 47.0% ground ball rate works in his favor. The team didn’t offer a timeline for his return, though it should be noted that forearm tightness is often a precursor to UCL damage and other serious injuries.

Isbel had been out for nearly two months with left plantar fasciitis. Prior to that, he batted .244/.298/.354 with an 80 wRC+ in 56 games. That’s pretty close to last year’s 79 wRC+, though he continues to hold value on defense, earning 4 Outs Above Average for his work in center field. Isbel has one more arbitration year remaining in 2027 and could be a non-tender candidate after the season if he continues to underwhelm at the plate.