Acquired in the Stephen Piscotty deal this offseason, Yairo Muñoz put himself in the forefront of Cardinals fans’ minds when he lit up spring training. With a .323/.364/.516 slash line through 23 games Muñoz became the 2018 José Martínez, unable to be denied a spot on the active roster headed into Opening Day in New York. What followed was a rough adjustment period to begin his Major League career.
The start of the season was terrible for Muñoz, as he went two-for-18 with 11 strikeouts in 20 plate appearances. Coupled with a few key defensive errors, Muñoz’s abysmal start led to a demotion to Memphis, as he clearly didn’t seem ready to handle big league pitching.
However, DeJong’s midseason injury paved the way for Muñoz to get another shot at a role with the club, this time in a temporary starting job. He ran with it. Since being recalled on May 19, Muñoz has hit .314/.365/.477, good for a 126 wRC+, tied for 63rd-best among hitters with at least 90 PA in that span. He’s dropped his K% to 18% after experiencing it climb to 55% before his mid-April demotion. His performance since being recalled has boosted his season wRC+ to 113, just ouside the top 100 among batters with more than 180 PA this season. He’s tied for 102nd-best with the likes of Justin Bour, Odubel Herrera and Travis Shaw — albeit in a much smaller sample size. A better comparison would be Greg Bird; Muñoz has 187 PA to Bird’s 185, and a 113 wRC+ to Bird’s 111. That performance isn’t front-loaded, either. Muñoz has gone seven-for-20 with a home run and three doubles in seven games since the All-Star Break.
The issue plaguing Muñoz at the start of his Major League career was one faced by many rookies: Making solid contact and putting the ball in play. As mentioned previously, Muñoz struck out in 11 of his 20 PA during his first stint with the club. Of his remaining nine plate appearances, Muñoz had seven batted ball events (BBE), two of which dropped for hits. Of his seven BBE, roughly 75% were pulled and were rated as soft or medium contact. As simple as it may sound, Muñoz started showing more selectivity with his pitches in his second stint with the club and enjoyed much better results:
Yairo Muñoz - Plate Discipline, 2018
In his current stint in St. Louis, Muñoz has lowered that near-75% Pull% to 33.9%; his batted balls go to center 39.5% of the time. His previous Hard% of 28.6% jumped to 37.9%.
A quick way to highlight Muñoz’s more selective approach is his performance with two strikes. Five of his first 20 PA went to 0-2 counts (25%), and he struck out four times with no hits in those at-bats. 35 of his 167 PA since May 19 have gone to 0-2, and he’s hit 11-for-33 with 13 K. In all two-strike counts, he went from one-for-15 with 11 strikeouts to 25-for-75 with 30 strikeouts. He’s consistently hit .333 when down to his last strike since his return to St. Louis.
Muñoz has even shown quite a penchant for hitting with men on base; his wOBA is .104 higher with runners on (.416) than with the bases empty (.312). The gap is .109 when comparing performance in high- or medium-leverage spots (.416) next to low-leverage (.307). He’s shown an ability to deliver when it counts.
Lastly, and perhaps one of the most important factors contributing to Muñoz’s utility, off-the-bench success, is that he shows no real weakness based on handedness matchups. Looking at the entire season, Muñoz has a 109 wRC+ in 59 PA against left-handers. What’s impressive is that his wRC+ is even better against right-handers, sitting at 115 through 128 PA. Given that his bat isn’t hyper-specialized, like Harrison Bader’s lefty/righty splits, Muñoz is a viable option to draw a start or pinch hit regardless of the handedness of the pitcher—an extremely beneficial aspect of his game, and one that exacerbates the value of his particularly special defensive versatility.
Playing Premium Positions
Aside from his bat, one of the things that made Muñoz so intriguing during Spring Training was his ability to play all around the diamond, infield or outfield. From the standpoint of evaluating performance at individual positions, he hasn’t been a knockout; combined across all positions, he’s been worth -6 DRS, with the bulk (-5) coming at shortstop and the remainder (-1) in center field. The important part is that he’s even been able to log time at both of those premium defensive positions.
The list of players who have logged any time at both SS and CF this season is just 18 names long. Of those players, only 11 have played at five or more positions total in 2018. Just three of those players have provided above-average offensive value. Those players are Kiké Hernandez, Chad Pinder and Muñoz.
Most of Muñoz’s defensive miscues came earlier in the season. But even looking beyond his below-average DRS at short and center, he’s played average defense at every other spot he’s manned. What’s more, it’s not like he’s been dreadful at those two premium positions; his ability to play steadily and slot in at multiple spots around the field, combined with positive production at the plate, makes Muñoz extremely useful.
What to Watch
A potential problem looming for Muñoz could be how he’s outperformed his xwOBA in his hot streak. In the May 19 - July 25 period, Muñoz’s wOBA - xwOBA is .049. Yes, speed is a contributing factor to outperforming one’s expected wOBA, and Muñoz’s 27.9 ft/sec is nearly a foot higher than the league average, but his gap between actual and expected performance is the fifth-highest in the majors (behind Harrison Bader, strangely enough). His .352 BABIP isn’t extremely far off from his minor league averages, and it’s possible that the combination of Muñoz’s speed and contact profile make for a player who will consistently outperform expectations. That’s an article for another day, or another writer. What’s visible to this point in the season is that Yairo Muñoz took a rough adjustment period, worked on his approach in the minors, and came back ready to contribute at the Major League level. Even though he’s contributed some negative baserunning value, the Cardinals have a 23-year-old bat capable of hitting righties and lefties, able to slot in anywhere in the defensive alignment, currently giving offensive production 13% better than the league-average hitter. If Muñoz has staying power and continues to develop, St. Louis has quite an asset for the next several years.