Under The Knife 4/14/25
It's Gotta Be The Velo, Money!
Working on a long intro and it’s just not going to make it in time for today. Look for more Wednesday or it might even turn into a Special as long as it’s getting. Let’s get to it:
JAKE CRONENWORTH, IF SDP (fractured rib)
It seems simple. Players have, for years, been hit in the ribs by pitches. It hurts, no question, but few are injured. Nasty bruise, but few extended issues. This year, we’ve had three separate issues of fractures, the latest being Jake Cronenworth. The simple answer is that pitchers are throwing harder, but was there some sudden tipping point? None of the pitches that hit these players were especially fast, like Ben Joyce and Aroldis Chapman are mowing down players as a tactic. 95+ is no longer unusual and hasn’t been for years, so as simple as it seems we can dismiss velocity as the simple answer.
What else might be causes? High spin and late-arm side movement. Cronenworth’s injury came on a 93.6 mph fastball from Ben Brown, spinning at 2,238 RPM — not elite velocity, but above-average spin. Murphy’s came off a 94.6 mph fastball from William Kempner, who’s now in High-A for the Marlins. In both cases, the hitters started to turn away from the pitch — the standard instinct — but the ball finished differently than expected, riding in late and catching them square in the lower ribs.
This isn’t just a two-case curiosity. Hit-by-pitch rates are already running hot again in 2025. Players like Hunter Goodman, Liam Hicks, and Cedric Mullins have already been hit eight times each, pacing the league in the first month. Goodman and Mullins, notably, seem to have a knack for absorbing contact without serious injury — an underrated skill worth paying attention to as the environment shifts.
League-wide, spin rates continue to rise. Fastballs now average over 2,300 RPM, and the old instincts hitters use to recognize inside pitches don’t necessarily hold up against pitches that stay on plane longer and move unpredictably late. Turning out of the way doesn’t protect you if the ball doesn’t fall where it’s supposed to.
It’s early, but the injuries to Cronenworth and Murphy suggest something important: The riskiest pitch to a hitter’s ribs may no longer be the fastest. It’s the one that moves the most. Cronenworth will miss at least 15 days but given he played with the fracture, his function might not be too affected. That suggests he could come back more quickly than “fractured rib” might read. Most players have missed around a month with similar injuries, so the Padres might elect to be cautious as well.
BEN JOYCE, RP LAA (inflamed shoulder)
Ben Joyce was never going to be boring. A college pitcher routinely topping 103 mph, touching 105.5, with a rebuilt elbow before he was drafted? There was only one way this story was going to go: fast and violent.
The news that Joyce is now dealing with a shoulder injury shouldn’t come as any surprise. If anything, it’s the most predictable next chapter in the ultra-high-velocity pitcher lifecycle. Joyce had Tommy John surgery at Tennessee, rebuilt the elbow, and came back throwing even harder (not because of the surgery, but because of maturity and hard work) and with that, shifted the breakdown upstream to the shoulder.
In general, extreme velocity pitchers blow out their elbows first. The UCL simply isn’t built to handle the kind of torque that 100+ mph pitches create, often topping 60 Newton-meters — brushing up against known limits of human tissue. But after Tommy John surgery, even perfect recoveries carry mechanical changes. Timing shifts, arm slots drift, and the kinetic chain gets out of rhythm just enough to start shoving extra stress into the shoulder. The labrum, the posterior rotator cuff, and the capsule all take hits that they weren’t designed to absorb.
Joyce was always at an even higher risk. His mechanics don’t look efficient in the way Jacob deGrom or Justin Verlander smooth their way to triple digits. Joyce is pure violence: late explosion, massive layback, no margin for error. That kind of delivery demands that every link in the chain holds perfectly. Tommy John rebuilds what was the weak chain; the force starts looking for what’s weakest now, usually working its way down. (Yes, I’ve seen some mechanical reports on Joyce.)
“Shoulder soreness” in a pitcher like Joyce usually isn’t just soreness. It’s a red flag for structural breakdown, most likely some combination of capsule instability and rotator cuff fraying. Whether it’s small tears, laxity, or subluxation, it’s serious. Shoulder injuries are harder to fix than elbows and far harder to predict outcomes from.
Throwing at this kind of velocity is absolutely unknown, an N of 1, maybe 2. The human arm isn’t engineered for it and no amount of training, strength, or stubbornness can change the basic physics. While we can train the arm to throw harder, we haven’t yet figured out how to make it last while doing just that. Joyce pushed right up against the limit and as always, the limit pushed back.