In Major League Baseball the bullpen is one of the most coveted positional groups, while also being incredibly difficult to construct. On a year-to-year basis, pitchers are changing things, working through kinks and trying to find something that can get outs. As the Philadelphia Phillies look to iron out the last few spots in the bullpen, newcomer John McMillon, and his elite-level stuff, is making his case during spring training.
The former Miami Marlin, who the Phillies claimed off waivers in November, dealt with some injury issues last season before being waived by Miami. Although he has been in professional ball since 2021, things have never seemed to fully click for McMillon, as major command issues stunted his development.
While he has faced adversity pitching in the minors with a 4.75 ERA and 7.1 BB/9, during two short stints in the majors, McMillon was up for the task, pitching to a 1.69 ERA in 16 innings with 2.8 BB/9. During his 10 appearances in 2024 for the Marlins, the Texas native retired the opponent scoreless nine times while only allowing a hit in half of his outings.
John McMillon has showed some nasty stuff early this spring, reminding us of former Phillie Jeff Hoffman
In just his first appearance with the Phillies in Grapefruit League action this spring, the 27-year-old instantly drew the attention of fans and data analysts alike. His plus-fastball and wipeout slider lit up the radar gun as well as the pitch profile models.
Much like another former Phillies no-named reliever turned All-Star, Jeff Hoffman, McMillon boasts a very good slider with a high-velocity four-seamer, consistently sitting near just under 100 miles per hour. Against the Baltimore Orioles in his spring debut on Feb. 23, the former Texas Tech Red Raider threw six of the seven hardest pitches in the game, all of which were over 98.6 mph, topping out at 100.2 mph. His fastball earned a proStuff+ of 134.
Babe, wake up— a new proStuff+ monster just dropped
— Pitch Profiler (@pitchprofiler) February 23, 2025
(don't look at his minor league walk rate) pic.twitter.com/NJFNRgN7yt
In his second outing against the New York Yankees, McMillon hovered around 96-97 mph, which was likely the doing of the coaching staff, hoping to ramp him up slowly as a precaution. Of course, the slider still was electric, reaching over 2,400 rpm. He struck out two in the ninth to close out the 7-7 tie on Thursday.
McMillon has now thrown two innings this spring without allowing a run with just one hit, one walk and three strikeouts.
Just slightly behind his top-level fastball is his slider, which had a proStuff+ of 131. In his appearance against the Orioles, McMillon had 33 or more inches of vertical break on each one he threw. This is when fans got excited. A pitcher pumping upper 90s with some command problems is almost commonplace in MLB at this point, but with a wipeout slider the same caliber as Hoffman's, McMillon's offers something you don't see every day.
Right now, the biggest thing holding McMillon back is the command issues. Luckily, the right-hander finds himself in the Caleb Cotham pitching factory with the hopes of cleaning up that part of his game. In just two years with the team, Cotham was able to cut Hoffman's BB/9 almost in half (5.2 down to 2.7)! With a couple of final bullpen spots still up for grabs, a few more electric appearances in Clearwater this spring could lead to McMillon finding his way North when camp breaks.