Athletics Outright Kyle Muller

Aug. 15: The A’s announced that Muller went unclaimed on waivers. He’s been assigned outright to Triple-A Las Vegas and will remain with the organization but no longer occupy a spot on the 40-man roster.

Aug. 13: The Athletics announced that Joe Boyle has been recalled from Triple-A Las Vegas. He will start tonight’s game against the Mets, per Martín Gallegos of MLB.com on X. In a corresponding move, left-hander Kyle Muller has been designated for assignment.

Muller, 26, was one of five players that the A’s received in December of 2022 in the three-team trade that sent catcher Sean Murphy to Atlanta, William Contreras to the Brewers and various other moving pieces. Muller had been considered one of Atlanta’s best prospects in the years leading up to that deal but had struggled to establish himself at the big league level and had just one option remaining.

The A’s gave him a decent amount of runway to take a major league job last year but Muller wasn’t able to capitalize on the opportunity. Through May 22, he had made 10 starts at the big league level but allowed 42 earned runs in 47 innings, leading to an 8.04 ERA. The A’s then optioned him to the minors, recalling him for one spot start in early July, but otherwise keeping him in Triple-A until mid-August.

The results on the farm weren’t much better, as he had a 7.26 ERA in his 13 Triple-A starts. He was recalled and worked as a swingman for the final few weeks of the big league season, tossing 25 innings with a 7.20 ERA in that time.

That left him out of options coming into 2024 and the A’s have kept in the bullpen for a long relief role. He missed just over a month on the IL due to left shoulder tendinitis but has logged 42 2/3 innings over 18 outings this year with a 4.22 ERA. That’s obviously an improvement over his results from last year and his 5.1% walk rate is quite strong, but there aren’t many positive metrics apart from that. His 19.7% strikeout rate is still subpar and his Statcast page is mostly blue, with not much to inspire confidence in terms of velocity, whiffs, avoiding barrels, etc.

Keeping him on the roster was going to be a long-term issue due to his out-of-options status and he hasn’t shown enough promise for the club’s decision makers to keep him around. With the trade deadline now passed, the A’s will have to put him on waivers in the coming days.

He has not yet qualified for arbitration and has five years of club control beyond this one, so perhaps some club will be intrigued by his past prospect pedigree, but they would be faced with the same roster restrictions that the A’s were. As recently as 2022, he was able to make 23 Triple-A starts with a 3.41 ERA, 29.3% strikeout rate, 7.4% walk rate and 45.9% ground ball rate, but the results have been far less impressive since then. He does not have a previous career outright nor does he have three years of service time, meaning he would stick with the A’s as non-roster depth if he were to pass through waivers unclaimed.

As for Boyle, it’s unclear if this is just a spot start or if he’s going to get a longer rotation audition. The A’s already had five starters in JP Sears, Ross Stripling, Mitch Spence, Joey Estes and Osvaldo Bido. Perhaps they could run a six-man rotation for a while or send someone down to Triple-A. It’s also possible that they put Stripling on waivers or move him to the bullpen. He’s a 34-year-old impending free agent and the club is out of contention, so they might prefer to give starts to younger guys that are in consideration for roles on next year’s club.

Boyle has a 7.16 ERA in the majors this year and a mark of 5.63 in Triple-A, but his work on the farm has been better of late. Back on June 28, he was demolished in his start against Sacramento, allowing eight earned runs while only recording four outs. Since that pounding, he has thrown 26 2/3 innings with a 2.36 ERA and a massive 51.5% strikeout rate, though a high walk rate of 12.9%.