Originally signed as an international free agent by the St. Louis Cardinals at the end of 2010, right-hander Luis Perdomo was just 17 years old when he made his professional debut in the Dominican Summer League in 2011. Perdomo pitched 19 innings in that first taste of pro baseball, striking out 16 batters, walking eight, and giving up 12 earned runs in total. It’s obvious those numbers aren’t good, but it’s hard to expect too much when you’re talking about a 17-year-old pitching professionally for the first time. After two so-so starts back in the DSL, Perdomo made his stateside debut in the Gulf Coast League. Despite his struggles in the DSL, Perdomo found a great deal of success in 47 and two-thirds innings in the GCL. Not only did Perdomo strike out 47 batters to just eight walks, but he also posted a groundball rate over 60 percent (a sign of things to come) and a home run rate of exactly zero.
Perdomo didn’t find nearly the same success back in the GCL in 2013. In 41 and two-thirds innings, Perdomo posted an ERA over 5.00 and saw a lot of regression in both his strikeout and walk rates, as evidenced by his 29:14 strikeout to walk ratio. The 2014 season was much of the same, as Perdomo struggled mightily in full-season ball after a short string of success to start the season in short-season ball. Perdomo threw 57 innings and posted a 5.05 ERA in Low-A. Perdomo once again posted a sub-par 41:21 strikeout to walk ratio. Perdomo also threw three innings in High-A to end the season.
In 2015, Perdomo spent the majority of the season back in Low-A, posting a career-high 100 plus innings. And Perdomo found some solid success, posting a 3.68 ERA and a 100:31 strikeout to walk ratio. However, Perdomo had some issues with the home run ball that lessened his overall success. Perdomo finished that year with 26 and a third innings in High-A, and once again posted an ERA over 5.00. Despite finding some success, the then 21-year-old starter went unprotected in the Rule 5 draft that offseason. Of course, Perdomo found himself selected in that draft by the Colorado Rockies and subsequently traded to the San Diego Padres.
Per Rule 5 draft rules, the Padres would have to keep Perdomo on the big league roster for the entirety of the season in order to keep him in the organization past the 2016 season. And the Padres did just that. Perdomo started in 20 games for the Padres, on top of 15 relief appearances, and threw 146 and two-thirds innings in total. Given that he was a 22-year-old who had never pitched above High-A ball, Perdomo was expected to struggle, and struggle he did. Perdomo posted a 5.71 ERA on the season as well as a home run/fly ball rate over 20 percent.
However, Perdomo did have some interesting splits worth noting. After posting an ERA just shy of 11.00 in April, over 9.00 in May, and over 7.00 in June, Perdomo posted respectable numbers in both July (3.99 ERA) and August (3.24 ERA). In fact, save for his step back in September (5.23 ERA), Perdomo improved his ERA in every month of the 2016 season. For a complete comparison, Perdomo posted a 7.48 ERA before the All-Star break and a 4.30 ERA after. Those numbers still weren’t great, but it painted a different picture of the season for the Rule 5 pick.
Going into 2017, Luis Perdomo was now officially a San Diego Padre moving forward, and he was looking to build off his late-season success in 2016. Rather than begin Perdomo back in the minors to restart his minor league development, the Padres decided to start him back in the bigs in 2017. Surprisingly enough, Perdomo was one of the Padres’ most consistent and durable starters last year, starting 29 games and throwing a career-high 163 and two-thirds innings. Although Perdomo posted a similar strikeout rate and saw a regression in his walk rate, he did post the best ground-ball rate of his career at 61.8 percent, saw a slight regression in his HR/FB rate, down to 15.6 percent, and posted an ERA over a full run less than the previous year.
Most importantly, Perdomo was consistent over the course of the season, posting ERAs between 4.40 and 5.00 in every single month. Those numbers don’t really jump off the page, but for a guy who never pitched in Double or Triple-A, league average starter numbers are quite surprising. With nearly three ground balls for every fly ball, Perdomo was able to have the most successful season of his career.
2018 Projection and Long-Term Outlook
Steamer: 26 games started, 153 innings, 16.8% strikeout rate, 8.4% walk rate, 56.4% GB rate, 4.33 ERA, 4.31 FIP, 1.8 fWAR
ZIPS: 25 games started, 148.7 innings, 17% strikeout rate, 8.2% walk rate, 4.48 ERA, 4.35 FIP, 1.7 fWAR
Although Perdomo has yet to be confirmed as a member of the Padres’ 2018 starting rotation, it appears that he has a pretty good chance of being one of the five players selected. According to the projections, Perdomo is projected to post very similar numbers to those he did in 2017. It’s hard to see Perdomo taking a huge step forward in 2018 because of the struggles he faced in 2017. With nearly 63 percent of his pitches being sinkers, and another 31 percent being sliders, Perdomo is largely a two-pitch pitcher, a proposition that usually doesn’t work out for starters. Although Perdomo did post great groundball rates the last two years, something he should continue to do if he continues to pound sinkers, batters have slashed .305/.368/.446 on his sinker so far in his professional career.
Without a more meaningful third pitch, it’s hard to see Perdomo being anything more than the league average-ish starter he has been the last two seasons. Although league average pitchers are valuable, Perdomo will have to take a step forward in 2018. With plenty of pitching talent on the cusp of big league relevance, Perdomo could be the odd man out come 2020 and beyond. However, he still has at least a full season, and more likely two, to work out the kinks and show himself as more than just a league average pitcher.