Paul Skenes’ four-seam spin rate sat at 2,318 rpm on a start in early April. By July 1, it had fallen to 1,987 rpm, a drop of roughly 330 rpm in three months, according to Baseball Savant data cited by justbaseball.com. His sweeper has bled spin over the same stretch, tracking the same downward line even if the exact number is less pinned down. This is not a two-start funk. It is a full-season line pointed in one direction, and the Pittsburgh Pirates just responded to it by pushing his next start back three days and calling it rest.
Start with what a 330 rpm spin loss actually does to a pitch. Four-seam spin is what fights gravity, the extra hop that makes a fastball look like it’s rising through the top of the strike zone even though it isn’t. Shave off that much rotation and the ball drops closer to where physics says it should, which means it arrives in the exact spot where hitters’ swings are built to meet it. Skenes’ velocity has followed the same script. His fastball averaged a career-low 95.7 mph in his last outing against the Marlins on Aug. 11, per MLB Trade Rumors, down from a season average of 96.8 and from 98-plus in each of his first two big league seasons. He touched 100 mph 100 times last year. He hasn’t sniffed it once in 2026.
The sweeper tells the same story from a different angle. Its average miss distance has fallen from 4.6 inches to 3.8, per justbaseball.com, which sounds small until you translate it: that’s the difference between a bat swinging through a pitch and a bat catching enough of it to do damage. Run values on his sinker and changeup have gone negative for the first time in Skenes’ career, according to Yahoo Sports/AOL, and opponents are hitting .228 with a .666 OPS against him this season, up from .198/.555 previously, per fansided.com, with a career-worst walk rate to match. Exit velocity allowed has climbed every month he’s pitched, from 86.7 mph in April to 87.8 in May to 89.8 in June, per the same reporting. Hitters aren’t just making more contact. They’re hitting the ball harder each time out.
I went back and forth on how much of this to chalk up to fatigue versus something more concerning, and the arm-angle data pushed me toward fatigue. Skenes’ release point has crept up three degrees this season, from 23 to 26, per MLB Trade Rumors, a subtle mechanical drift that shows up when a pitcher is compensating for tired legs or a tired core, not something structural. More telling: after seven days of rest around the All-Star break, he touched 96.7 mph in his return, well above his season average. Extended rest appears to actually work. That’s the case for optimism buried inside a discouraging trend line, and it’s also the case Pittsburgh is making by pushing this start back.
How Much Has Paul Skenes’ Velocity Actually Dropped?
His fastball has gone from averaging 98-plus mph across his first two seasons to 96.8 this year, with a career-low 95.7 mph outing on Aug. 11 against the Marlins. He touched 100 mph 100 times in 2025 and hasn’t reached it once in 2026, per MLB Trade Rumors and justbaseball.com.
What Do the Spin Rate Numbers Say?
Four-seam spin fell roughly 330 rpm between an April 1 start and a July 1 start, per Baseball Savant data cited by justbaseball.com. His sweeper has followed the same downward path, with its miss distance shrinking from 4.6 inches to 3.8. Both losses track directly with weaker miss rates and harder contact allowed.
The Pirates’ explanation, delivered by manager Don Kelly, is that the move is “not injury-related.” Skenes’ start against the Red Sox got pushed to Wednesday against the Tigers, with a bullpen game filling Sunday.
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Skenes himself offered the mildest possible endorsement: “I don’t necessarily disagree with the decision either.” He was pulled after just 65 pitches in that Aug. 11 outing, despite allowing only one earned run over five innings, a workload management decision far more conservative than the box score demanded.
What actually separates this from a normal midseason maintenance day is the standings. Pittsburgh has lost 18 of its last 28 games. This site already flagged the warning signs back on July 2, when his spin was already sagging and his ERA over a nine-start stretch had ballooned to 5.36. That was written during a stretch when the Pirates were flirting with relevance and every start carried playoff weight. None of that weight exists anymore. His ERA now sits at 3.88 through 25 starts, a number that would have been unthinkable during his sub-2.00 rookie stretch.
Why ‘Rest’ Means Something Different for a Non-Contender
A contender resting its ace protects a playoff run. Pittsburgh has nothing left to protect this season, so the same three extra days of rest function as asset management, buying time to figure out what’s wrong with a 23-year-old cornerstone before next spring, not shepherding a pitcher toward October.
That distinction matters more than the injury denial does. When a team with something to play for rests a healthy ace, it’s precaution. When a team with nothing to play for does it, the calendar itself is the tell. There’s no wild-card math left to protect, no rotation order that needs preserving for a series in October. The only thing left to manage is Skenes’ value going into an offseason where the Pirates front office has to decide whether this is fatigue, a swing-thought fix, or something that requires an actual diagnosis.
The honest counterargument here is that elite starters go through velocity dips all the time, particularly in August, and a bad month of contact luck can make a perfectly healthy arm look compromised. That’s a fair read of any single bad start. It doesn’t survive contact with a spin-rate decline that spans April through July across two different pitches, correlates with a rising arm angle, and reverses, even partially, whenever Skenes actually gets extended rest. One bad month is noise. A four-month trend that responds predictably to rest isn’t noise, it’s a signal the Pirates are already reading, whether or not they’ll say so out loud.
Watch what happens to his velocity Wednesday against the Tigers. If the extra rest pushes him back toward 97-98 mph the way the All-Star break did, Pittsburgh will keep calling this maintenance and keep buying extra rest days the rest of the way. If the fastball is still sitting in the mid-90s, the conversation stops being about rest and starts being about what an MRI would show.
