A former 2nd-round pick from the 2016 Draft, Muller had spent the entirety of his pro career in the Braves’ system slowly rising the ranks, finally cracking the majors in 2021 for eight starts for Atlanta. He looked solid during his rise up the minor leagues and topped out as the Braves’ fourth-best prospect at the time of the trade.
Muller came to Oakland as the headline return piece from the Sean Murphy trade to Atlanta, along with outfielder Esteury Ruiz and pitchers Freddy Tarnok and Royber Salinas. Muller and Ruiz made the Opening Day roster while the other two began the year in the minors.
What were the expectations?
Entering Spring Training we didn’t know if Muller would be able to crack the Opening Day rotation. Muller had had a handful of appearances the previous two years for the Atlanta Braves but now he’d be getting a legitimately long look in the big leagues. So it was a fairly significant surprise when it was announced that he’d earned the Opening Day nod. Expectations definitely rose after that announcement.
Well, his Opening Day assignment went very well as he held down for five innings a then-healthy Angels team that had Mike Trout, Shohei Ohtani, and Anthony Rendon. Over the next month he had a couple good outings and a couple real duds, but things really fell apart in May. Over four starts in May he pitched to an almost unbelievable 10.80 ERA in just 18 ⅓ innings. The team had seen enough of the lefty and demoted their Opening Day starter to Triple-A to knock out the kinks.
He spent the next couple months with the Aviators (save for one quick spot start for the A’s) but looked like the same pitcher who was getting ambushed constantly. Oakland, desperate for pitching, brought him back up for good in August but he would spend the rest of the season in the Oakland bullpen. He was mildly better as a reliever but still below-average.
The soft-tossing Muller was never expected to be a strikeout artist, instead relying on command and control to keep hitters off balance. Still, his already low strikeout rate fell to the lowest mark of his pro career while his walk rate went up almost two full points compared to 2022. You would have hoped he showed more life down the final stretch but any improvement didn’t show up on the box scores.
Muller didn’t end the year on a great note but the club invested a lot in the young left-hander when they made the trade for him. Now, though, there is a lot more competition on paper now. There could be as many as eight candidates for a season-opening rotation job on the roster, including Muller. He’ll be fighting tooth and nail to regain his standing with a club desperate for pitching. They’ll be hoping Muller comes to camp with a renewed sense of urgency to take the next step in his development. Otherwise, the minor leagues await.