Kyle Muller has long been my favorite prospect, and alas his time has come… maybe. Called up for the first time in 2021, Kyle pitched in 9 games throwing 36.2 innings with a 4.17 ERA. Nothing to write home about, but not too shabby for his first cup of coffee. As has been the problem for Muller throughout the minors, his control issues persisted in the majors. He surrendered almost as many free passes as he did hits and added 9 wild pitches.
Muller was ranked as the Braves 5th prospect at the last MLB Pipeline update, just above fellow lefty Tucker Davidson. At 6’7” and 250 pounds Muller is a force to be reckoned with on the mound. Muller has not yet cracked the top 100 list, but I think he’s on the cusp and there is potential he could find himself on the 2022 list when it’s released. His best pitches are his fastball that can reach triple digits and his curveball, but he also has a slider and changeup that continue to improve. It would be great to see him show up to Spring Training as a legit 4-pitch pitcher. Definitely more important than adding the extra pitches, Muller needs to take a big step forward on control. At the previous MLB pipeline update his lowest ranking tool was his control at 45, compared to his fastball/curveball at 65 and 55 and his overall a 50.
Muller split his time almost exactly 2/3 in Gwinnett and 1/3 in Atlanta in 2021. He was almost an identical pitcher at both levels. He held a much lower 3.39 ERA in his 79.2 AAA innings, but his runs/9 were 4.18 and his BB/9 and H/9 were almost identical with a slight uptick in K/9. The cause for the most concern is the wild pitches. Kyle had 15 wild pitches in AAA and the aforementioned 9 in the MLB. He also had 37 wild pitches in his previous 4 minor league seasons combined. It’s clear Muller has knock out stuff and the results have shown, but he has struggled with getting deep into games and will have outings where he simply gets blown up. Of his 26 combined appearances in 2021, just 7 resulted in 3+ runs. That’s fantastic, except he only made it through 5+ innings in exactly half of those appearances, mainly attributable to the number of walks he allowed and how deep he gets in pitch counts.
I would love to see Muller show up in Spring Training with a full offseason of work under his belt ready to compete. If he can lower his BB/9 from 5 to something like 3.5 this season he would be in for a monster year. Fangraphs is projecting him to have a similar year to 2021, spending most of it in AAA and making around 10 starts and throwing 40-50 innings with similar results. Spring Training will be a battle (if this lockout ends and we actually get Spring Training), but I wouldn’t be shocked whatsoever to see Muller break camp with a spot in the rotation, and if he does, I would keep a close eye on him. This kid has the tools to be special in the bigs, it all depends on if he can take what he learned and improve.