Reynaldo Lopez

Lopez was a setup man for three different teams in 2023, splitting time between the White Sox, Angels by way of a trade, then Guardians via waiver claim. The 29-year-old compiled a career-best 22 holds and six saves while demonstrating increased velocity on his four-seam fastball that he threw 98.2 mph on average. He relied on the pitch more than ever, throwing the heater a career-high 64.3% of the time with excellent results (.188 BA, 46 strikeouts). After closing out 2023 with a scoreless month of September (11 innings), the right-hander finished with a respectable 3.27 ERA along with 83 strikeouts, his most as a full-time reliever. However, after Atlanta signed Lopez to a 3-year pact, beat writers have reported he will stretch out during spring training to possibly contribute as a starter and reliever. Given his career splits as a starter (4.73 ERA) versus reliever (3.01 ERA), one would think Lopez will hold a setup role once again.

After five-and-a-half years of struggling to make it as a starter, Lopez made the transition to full-time reliever in 2022 with 60 of his 61 appearances coming out of the pen. The right-hander demonstrated increased velocity on all four of his pitches, including an extra 1.3 mph on his fastball for a 97.1 mph average (93rd percentile), plus another 3.5 mph on his curve. He had great results too, posting six wins, nine holds and career-best ratios across 65.1 innings. Lopez's strikeout rate was consistent with 2021 and slightly above average at 24.8%, but he really made strides with his control and home run rate. His 4.3% walk rate and 0.14 HR/9 were also career-bests, with the latter tied for the best among qualified relievers after giving up just one home run last season. Lopez has the upside to close, but with Liam Hendriks and other veteran relievers to contend with in Chicago, don't count on an abundance of saves chances in 2023.

Evaluating Lopez requires a look beyond his season-long stats, as his 20 appearances in the majors were split nearly exactly evenly between starting and relieving. As a starter, Lopez posted a strong 15.4 K-BB% though his 4.10 ERA was likely fortunate given that he surrendered 1.7 HR/9. However, Lopez really made his mark as a reliever. In 20.1 innings of work, Lopez predictably saw his K% spike to 30.1, and he surrendered a more respectable 1.3 HR/9. Despite the positives, it's also important to keep Lopez's relative success in perspective. For one, this small run of success comes in the face of a career that has been dominated by struggles to this point. Lopez's success also came in largely low-leverage roles as he failed to log either or a save or hold. His performance was likely enough to save his future in the majors, though his path to consistent fantasy value is less clear given the strength of the White Sox bullpen and Michael Kopech's likely move to a full-time role in the rotation.

Lopez's 2020 campaign was derailed by a combination of injury and poor performance that led to a brief demotion to the team's alternate site. He ended the season with a 6.49 ERA that was marred by a 12.4% walk rate and 3.1 HR/9. On a positive note, Lopez incorporated both his slider and changeup more heavily. After throwing his fastball at or near a 60% clip through the first four seasons of his career, Lopez's fastball usage dipped to just over 50% in 2020. As a result, he threw three different pitches at a 20 percent or higher clip for the first time in his career. New pitching coach Ethan Katz could help Lopez build on this tweak to improve his results in 2021. A positive trajectory will be necessary for Lopez to remain in the rotation, as Michael Kopech will return in 2021 and the team could look to add to their staff in free agency as well.

In 2018, Lucas Giolito posted the worst ERA among qualified starters. While Lopez's 5.38 ERA wasn't the worst of 2019, he was next in line, with only Rick Porcello's 5.52 mark being higher. If you squint, there's a glimmer of hope for Lopez. His 4.88 SIERA suggests the actual 5.38 ERA was unlucky. More importantly, Lopez's second-half skills improved, fueling a 4.29 second-half ERA (6.34 before the break). Specifically, Lopez's strikeout rate improved to 22.5% from 19.5%, his walk rate dropped to 7.3% from 8.5% and his HR/FB plummeted to 1.26 from an unsightly 2.11. Lopez's fastball velocity is 83rd percentile, but he lacks spin on both it and his curve. Their respective spin rates rank 22nd and 7th percentile. Lopez's breakout potential is far from "roster at all costs." However, if you have a deep reserve, consider stashing Lopez and monitoring spin rates and performance early in the season.

Lopez closed out the year with an outstanding run in September (1.09 ERA), bringing his ERA for the season under 4.00 after it got as high as 4.72 in mid-August. Was it mostly luck, or did Lopez actually figure something out down the stretch? He said last summer that he was focusing on the mental aspect of the game instead of just trying to blow by hitters, continuing lessons instilled by Max Scherzer about scouting hitters, locating and changing visual angles. An important aspect of Lopez's development has been the slider that White Sox pitching coach Don Cooper taught Lopez in 2017. It has since become Lopez's best pitch by Pitch Values. Lopez's strikeout rate soared to 27.6% over the final month, and while it may have been mostly fluky, part of it may have been his maturation as a pitcher and the more granular scouting of his opponents. Further refinement of the changeup is still needed, but there is plausible upside here.

Acquired from the Nationals last offseason in the Adam Eaton deal, Lopez is one of many power arms the club has stockpiled. After 22 starts for Triple-A Charlotte, registering a 3.79 ERA and 1.24 WHIP with 131 whiffs in 121 innings, Lopez got the call to the majors, making his Pale Hose debut on Aug. 11. Lopez started eight contests, working at least six stanzas in all but one, an impressive feat in today's five-and-fly climate. A 65 percent left-on-base rate didn't do his ERA any favors, though a weak 15 percent strikeout rate didn't help either. Lopez displayed an above-average strikeout clip everywhere else, including a short stint with the Nationals in 2015, so expect the righty and his 95-mph fastball to pick up the pace as he further acclimates to major-league hitters. Lopez has the stuff to be a difference-maker down the line. For now, there will still be growing pains, working half the time in one the American League's friendlier hitting venues.

After dominating Double-A to begin the season, Lopez spent the second half bouncing between Triple-A and the majors, posting solid ratios at Syracuse despite a decline in his strikeout rate but mostly struggling for Washington. He flashed his upside in August, though, posting a 1.29 ERA and 13:4 K:BB in 14 innings over back-to-back starts against the Braves. The 22-year-old right-hander's big weapon is a fastball that averaged 95.8 mph in the majors, but he also mixes in a plus curveball and work-in-progress changeup. There are concerns about his ability to hold up as a starter given his slight frame, but his arsenal should allow him to thrive in a late-inning role if he is eventually moved to the bullpen. Traded to the White Sox in the Adam Eaton deal, Chicago will give Lopez every chance to stick as a starter, and a strong spring could put him in the rotation to begin 2017.

A year after a breakout performance that landed him near the top of the Nationals' prospect list, Lopez is still more future projection that he is finished product. His 4.09 ERA and 8.5 K/9 in 99 innings at High-A Potomac weren't exactly dominant, but his 2.5 BB/9 and 0.5 HR/9 indicate an ability to keep the ball in the lower half of the strike zone that will serve him well as he advances through the system. The 22-year-old right-hander fires a heavy high-90s fastball from an easy, repeatable delivery, and his curveball and changeup both have the makings of above-average pitches. Six-foot pitchers with big velocity tend to get typecast as relievers, and that could well be Lopez's eventual fate, but his athleticism and secondary offerings are strong enough to give the Nats every reason to keep him in the rotation as he works his way up the ladder.

Signed out of the Dominican Republic in 2012 as an 18-year-old, Lopez raced up prospect lists after a breakout season in which he struck out 70 batters in 83.1 innings between the New York-Penn and South Atlantic leagues. The right-hander features a heavy mid-90s fastball that he can crank up to near triple digits when he feels the need, plus a work-in-progress breaking ball and changeup, and if everything comes together, he'll give the Nationals yet another future ace to slot in alongside Stephen Strasburg and Lucas Giolito. Lopez is a long way from being in their company, though, and even the Yordano Ventura comps getting bandied around are very premature. The kid has massive upside, and that fastball is as close to a guarantee of a big league job as you'll find, but you may want to wait and see if he can dominate over a full season before anointing him as the next big thing.