In late July of the 2021 season, the Houston Astros acquired closer Kendall Graveman from from the Seattle Mariners for Abraham Toro and Joe Smith, but Graveman wasn’t the only reliever in the return.
Rafael Montero, then recently designated for assignment by the Mariners, looked to be a thrown-in arm for a bullpen eyeing high-leverage need. In four appearances totaling six-scoreless innings, Montero made a statement in smaller situations with five strikeouts to two walks, before hitting the injured list with a shoulder strain.
Montero attempted a comeback in the postseason, throwing bullpens in October at Minute Maid Park, but the right-hander remained away from live competition until spring training. Due to travel issues, the 31-year-old made one appearance in March, granting two earned runs on nine pitches.
The right-hander returned to the bullpen on time, making seven appearances as of Sunday afternoon. Montero has worked seven-scoreless innings with five hits — none for extra bases — and no walks to 13 strikeouts, while making five of his seven appearances with a one-run lead or in a tied ballgame.
In part to Ryne Stanek, Phil Maton and Hector Neris being unavailable at different points in the young season and Ryan Pressly being on the shelf, the Astros are putting more trust into Montero. Luck plays a part early on, but in correlation to his 0.00 ERA, Montero displays a -0.63 FIP, one of the best in Major League Baseball according to Baseball-Reference.
What is Astros reliever Rafael Montero doing differently from years past?
According to Baseball Savant, Montero ranks above average in all advanced percentiles, except chase rate and average exit velocity. Sitting in the 100th percentile of xERA, K% and xwOBA, the righty is masterfully working at-bats, although giving into a 90.4 mph average exit velocity.
Command is Montero’s best friend according to Predicted Pitch Quality, but for Batting Average in Balls in Play (BABIP), the righty sits at .357 in a sample size of 14. Of those five hits, four of them had an xBA north of .500, while two of the nine outs in play — both line outs — had xBAs better than the league average.
With success to open the year, Montero is showing a 26.5% increase in fastball usage, throwing the heater 62.2% of his four-pitch arsenal, likely contributing to less chase rate. His three offspeed pitches — sinker (almost exclusively to righties), changeup (almost exclusively to lefties) and slider — have all seen a decrease in usage with the sinker losing roughly 11% of its time over the plate.
Velocity is neighboring recent years, while showing extra ticks of mph early on. But the pitch that hitters are eating is the changeup, a pitch Montero is seeing an .742 xBA and a 50 HardHit%. This could be a factor of inconsistent release points with the pitch, but besides the changeup, Montero’s fastball, sinker and slider are all sub-.200 xBA for balls in play.
Pitching coaches Josh Miller and Bill Murphy look to be carrying over what Brent Strom offered Montero, as the Astros are seeing an emergence of another high-leverage alternative.