It wasn’t a reunion with old friend Johnny Cueto, but the Reds added a veteran pitcher to their staff on Friday by signing right-hander Luke Weaver to a one-year, $2 million contract. The club designated utility player Matt Reynolds for assignment to clear a spot on the 40-man roster.
The 29-year-old Weaver is a seven-year MLB veteran who has pitched for three different teams. Across 450.2 career innings, he holds a 4.79 ERA, 3.96 FIP, and 4.07 xFIP. After three seasons pitching for Florida State University, he was selected with the 27th overall pick in the 2014 draft by the Cardinals and made his big-league debut in 2016 at 22 years old. Weaver was a top-100 prospect in baseball entering the 2017 season, when he split his time between Triple-A and the majors. He pitched well in his MLB starts, posting excellent strikeout and walk rates (28.6% and 6.7%) that led some to believe Weaver was due for a breakout in 2018. As a full-time member of the St. Louis rotation, he took a step back in 2018, however, as his strikeouts plummeted and his walks increased.
The disappointing season made Weaver expendable in the Cardinals’ eyes, and he was traded to the Diamondbacks as part of the Paul Goldschmidt deal. Although Weaver was effective in 2019 — posting a 2.94 ERA, 4.23 xERA, and 3.87 xFIP — he made just 12 starts as he missed more than three-and-a-half months with right forearm tightness. Healthy for the truncated 2020 season, Weaver struggled to the tune of a 6.58 ERA, 4.77 xERA, and 5.06 xFIP. As he looked to rebound in 2021, an injury hampered him again. He made only 13 starts, missing three-and-a-half months due to a right shoulder strain. Weaver was again penciled into the Diamondbacks’ starting rotation to begin the 2022 campaign, but he left his first start of the year with right elbow inflammation. When he returned in June, he transitioned to a relief role. He was later traded to the rebuilding Royals. Weaver finished the 2022 season with a disappointing 6.56 ERA and 5.45 xERA in 35.2 innings.
The Mariners claimed Weaver off waivers in October but non-tendered him weeks later. The Reds signed him for $1 million less than he was projected to earn in arbitration, according to projections by MLB Trade Rumors.
In terms of eating up innings, it remains to be seen how effective Weaver can be. He’s had some form of right arm injury in three of the last four seasons, limiting him to 216.5 innings in that span. The Reds are surely not counting on him to come in and throw 150+ innings in 2023.
In terms of performance, there are some encouraging signs underneath the hood — as well as some not-so-encouraging signs.
Looking Beyond ERA
If we just looked at ERA and nothing else, the conclusion to the question posed above would be a resounding “no.” But as you know if you’ve read RC+ before, there are better ways to evaluate a pitcher. Let’s start with a couple already cited above.
Weaver posted a 5.45 xERA in 2022, which isn’t exactly inspiring. This metric uses batted-ball data from Statcast — as well as strikeouts, walks, and hit by pitches — to estimate what a pitcher’s ERA should be based on the average results of similar batted balls league-wide. It’s not a surprising result given that Weaver has ranked in the bottom 25% of the league in average exit velocity and hard-hit rate allowed in every season since 2019. Weaver’s season may have looked even worse if he didn’t have good home run luck. Despite owning a below-average ground-ball rate (40.0%) and giving up a lot of hard contact, he allowed only one home run. Statcast estimates that Weaver would’ve allowed six home runs if he pitched all his games in Great American Ball Park.
However, Weaver’s 3.82 xFIP was much more palatable. Unlike xERA, xFIP assumes a pitcher doesn’t have control of what happens when a ball gets put into play and instead measures for factors they can control: strikeouts, walks, and hit batters. It also factors in home runs. Whereas FIP is calculated to assume pitchers have control over home runs, xFIP normalizes it by using the league average home run to flyball ratio. Weaver had a strikeout rate below average for a reliever (21.8%) and a dip from his career norms (23.4%), but his walk rate was strong (7.5%) as it has been for his entire career.
How we evaluate Weaver on these two peripherals depends on whether you feel pitchers have control over the quality of contact they allow. There’s some evidence that pitchers do have at least some control over it, though not fully. In the absence of a more perfect measurement, perhaps splitting the difference is the best way to view the ERA estimators. Simply taking the average of xFIP and xERA would put Weaver at an estimated 4.63 ERA in 2022.
While we’ve looked at some of Weaver’s peripheral numbers, none of this really explains why there was such an extreme gulf between his ERA and xFIP despite a low home-run rate. The answer lies in his .429 batting average on balls in play. Allowing a lot of hard contact will certainly inflate a pitcher’s BABIP, and Weaver’s career BABIP is high (.328). But the territory Weaver was in last year shows some rotten luck may have come into play, too. Weaver allowed an average exit velocity of 91.5 mph — which, make no mistake, is not good. But even with that caveat, his xBA (expected batting average) allowed was .292 — again, not good at all, but not as bad as his BABIP indicated.
To recap where we’re at so far: Weaver gives up more hard contact than the average pitcher, but he can mitigate it somewhat by throwing a lot of strikes and — in previous years at least — a respectable number of strikeouts.
Let’s look even deeper under the hood at Weaver’s pitch arsenal.
Weaver threw six different pitches last year, but he mostly stuck to a fastball-changeup combination, throwing one of the two 86% of the time. He also has a slider in his repertoire, along with a seldom-used curveball, cutter, and sinker.
Despite the arm injuries, Weaver hasn’t lost anything on his four-seam fastball, which is a positive sign that he indeed has something left in the tank. He’s consistently hovered between 93 and 94 mph throughout his career. After a dip in 2021, his average fastball velocity ticked up to a career-best 94.9 mph as a reliever in 2022.
Through his two rehab outings in Louisville this year, Weaver’s fastball has averaged 93.0 mph. A velocity dip is to be expected as he transitions back to starting, but this will be something to monitor.
In 2020, Weaver “revamped” his fastball to get more spin, jumping from the 58th percentile in spin rate to the 87th. Sticky substances may have been in play, but even in 2022 — after the league cracked down on foreign substances — his fastball spin ranked in the 82nd percentile. In his two rehab outings in 2023, his fastball spin rate has stayed consistent with last season, which is a good sign. High-spin fastballs are effective when thrown up in the zone because hitters tend to swing underneath them. Still, Weaver’s whiff rate on the pitch (21.9%) wasn’t anything exciting, sitting at almost exactly league average.
There’s room for improvement here, particularly if he can recapture his former spin efficiency on the pitch. Higher spin efficiency typically translates to more movement; for a four-seam fastball, that means staying higher in the zone for longer and potentially more whiffs. Weaver’s spin efficiency on the four-seamer was an excellent 98% in 2020, but it dropped to 95% in 2021 and 92% in 2022. That’s one area that Reds pitching coaches could help Weaver address via an arm angle and/or grip adjustment.
For what it’s worth, Weaver’s fastball has rated as average over the last three seasons according to Stuff+, and it dipped to below average last season even with a velocity increase. However, his ability to locate it has been consistently strong (104 Location+ since 2021).
Using Statcast’s pitch value metric, Weaver’s changeup has been a great pitch for him at times (2017, 2019, 2020), and it’s been a terrible pitch at others (2018, 2021). The Pitching+ model mostly agrees. Last year, the pitch was just OK. But it did show some signs of getting back on track.
He improved his command of the changeup in 2022, with its Location+ jumping four points from 2021. He also re-added vertical movement to it. Between 2019 and 2020, Weaver lost 4.5 inches of drop on his changeup and it went down further in 2021. In 2022, however, he added nearly four inches of vertical movement back to the changeup. While that still put him in average territory compared to other pitchers, it helped his whiff rate tick up:
More vertical movement also meant more meant more ground balls and less hard contact. Those factors, paired with better command (i.e., fewer changeups in the middle of the plate), helped his xwOBA tick down to its lowest level since 2017:
You can check out the difference in his changeup below — note how flat the pitch looked in 2021 compared to 2022.
While many pitchers prefer to throw changeups to opposite-handed batters, Weaver is comfortable throwing it against right-handed batters and does so about 20% of the time.
Will the improvements hold up as a starter? It remains to be seen.
Weaver lacks a dependable third pitch, however. He’s used a curveball and cutter as his third pitch in the past. Last year, he began throwing a slider that proved very ineffective with a dismal 8.3% whiff rate, worst among all MLB pitchers who threw at least 70 sliders. It was also below average according to the Pitching+ models. While he could scrap the pitch, Weaver seemingly has something to work with: his slider got 4.2 inches of drop above average. That’s comparable to Graham Ashcraft (4.4 inches above average), and it ties Weaver for 42nd among 500 pitchers who threw at least 50 sliders. It’s certainly not insignificant. The pitch is lacking on horizontal movement, however, coming in at 1.8 inches below average.
Perhaps another offseason to work on his command of the slider could yield better results, whether that means further altering its shape, changing his pitch sequencing, adjusting his arm angle, or something entirely different.
Other than Chase Anderson, Weaver has the most MLB starting experience of any pitcher the Reds could put in the fourth or fifth spot in the rotation. But there are more questions than answers for him right now. There were some encouraging signs under the hood last year — but were they enough to say he can be an effective pitcher again? Not with a ton of confidence, although his command was at least above-average in 2022, if nothing else. Weaver will also have to prove his arm can handle the workload and that he can still be effective in longer outings.
Could Weaver flop and end up as a low-leverage reliever or DFA candidate? It’s within the range of possible outcomes. But for just $2 million, there’s seemingly enough left in his arm to take a shot and let the Reds’ pitching coaches try to work their magic.
Featured Photo by Daniel Hartwig