The Astros and Phillies sit atop their respective divisions despite weathering injuries to some of their top pitchers, and now both teams face the prospect of finishing out the regular season — or perhaps going even longer — without one of their best. On Tuesday, the Astros placed Josh Hader on the 15-day injured list with what was initially described as a shoulder strain; on Friday, they clarified that he has been diagnosed with a shoulder capsule sprain. On Saturday, the Phillies announced that Zack Wheeler had landed on the IL due to “a right upper extremity blood clot” near his shoulder.
The Wheeler injury is the more serious of the two, as blood clots can be life-threatening if untreated, and career-threatening even if they are. Fortunately, it sounds as though the Phillies’ medical team caught this one before it could become an even more serious situation. Wheeler had struggled to some degree since throwing a 108-pitch complete-game one-hitter on July 6 against the Reds, with his ERA and FIP rising as his velocity trended downward. His scheduled August 8 start against the Rangers was pushed back by two days due to shoulder soreness. An MRI taken at the time came back clean, but even so, he set season lows for the average velocity of all six of his offerings once he finally took the mound on August 10.
Zack Wheeler grinded his way through 5 innings to get his 1st win in more than a month … but his velocity was down significantly and his fastball command continued to elude him.
There will be a lot of eyes on his next start. pic.twitter.com/IIF2mSnR0V
— Paul Casella (@Paul_CasellaMLB) August 10, 2025
Both Wheeler and manager Rob Thomson downplayed concerns about Wheeler’s waning velocity at the time. While the 35-year-old righty’s velocity rebounded by 1-2 mph in his August 15 start against the Nationals, he struggled with his command and lasted just five innings for the second start in a row — the first time all season he’d failed to go longer than five in back-to-back starts. Afterwards, Wheeler reported feeling “a little heaviness” on his right shoulder, and an examination on Saturday revealed the blood clot. “Yesterday, some symptoms had changed,” said head athletic trainer Paul Buchheit on Saturday. “Doctors were great in helping to diagnose and expedite that diagnosis this morning.”
“I commend Paul and the doctors here to find this because it could have been a much more trying situation than what it is,” said president of baseball operations Dave Dombrowski.
Wheeler will undergo further testing and evaluation in Philadelphia this week, after which the Phillies will be able to offer a more detailed prognosis, but for now there’s no estimate as to when he’ll return. “We don’t know the timeline,” Thomson said. “I’m thinking a lot about Zack and his family because this is not a hamstring injury or something like that.”
Sometimes such clots require surgery to remove the first rib, which can compress the subclavian vein or subclavian artery under the collarbone, a situation similar to thoracic outlet syndrome. At Under the Knife, Will Carroll offered examples of several pitchers who dealt with such clots and underwent rib removal and successfully returned, including Aaron Cook (2004), Alex Cobb (2011), Dillon Gee (2012), and Mike Foltynewicz (2015):
The surgery path, if taken, is essentially the same as TOS surgery. The difference is that Wheeler is older than most pitchers who’ve gone through it, which raises the stakes. At 35, recovery time isn’t just about healing, it’s about how much is left in the tank once he’s back. He does profile well as the kind of pitcher that could coast in his late career like a Max Scherzer or Clayton Kershaw.
Until now, Wheeler has been the picture of durability, making just two trips to the injured list in the last seven seasons: In 2019, he missed two weeks around the All-Star break due to shoulder fatigue, and in ’22, he missed four weeks due to forearm tendinitis. Since the start of the 2019 season, only three pitchers have topped his 188 starts, and no pitcher has thrown more innings than his 1,174.1 frames. He’s the runaway leader in WAR over that span:
Pitching WAR Leaders Since 2019
Wheeler owns a similarly large lead in Baseball Reference WAR over the same timeframe, with 33.8 to Cole’s 26.4 — perhaps a point in his favor when it comes to his Hall of Fame chances down the road. After finishing second in the NL Cy Young voting last season, he’s in the midst of another fine season, making his third All-Star team and leading the NL in xERA (2.44), strikeouts (195), strikeout rate (33.3%), and strikeout-to-walk differential (27.7%). He’s also fourth in FIP (2.98) and WAR (4.0), and fifth in ERA (2.71).
That’s the kind of pitcher a playoff-bound team — as the Phillies, who own a five-game lead in the NL East and Playoff Odds of 99.1%, appear to be — counts on to be its Game 1 starter. Indeed, Wheeler has taken the ball for five series openers in the past three postseasons and generally pitched brilliantly in that context, allowing three runs in 33 innings. He’s got a reasonable case as the best postseason pitcher of the past decade, with a 2.18 ERA and 2.72 FIP in 70.1 innings. You don’t replace such a pitcher easily, though the Phillies do at least have a strong supporting cast in what’s been the majors’ strongest rotation according to FIP (3.42) and WAR (15.6).
Along with Wheeler, both Cristopher Sánchez and Ranger Suárez are in the midst of strong seasons themselves, with Sánchez second in the NL in WAR (4.3) and third in ERA (2.45), and Suárez ranking among the top 15 of NL pitchers with at least 100 innings in both ERA and FIP (3.28 and 3.27, respectively). Jesús Luzardo has been solid, with a 4.21 ERA, 3.11 FIP, and 3.5 WAR, the last of which ranks fifth in the league.
On the other hand, Aaron Nola has been terrible. Activated on Sunday after missing three months due to a right ankle sprain and a stress fracture in one of his ribs, he was rocked for seven hits and six runs by the Nationals in 2.1 innings, raising his season ERA to 6.92 and his FIP to 4.87, both career worsts; he’s allowed a career-high 1.9 homers, with his lowest strikeout rate (23.8%) of any season since his 2015 rookie campaign.
The Phillies had planned to create a six-man rotation by adding Nola to a unit rounded out by Taijuan Walker, who has pitched to a 3.34 ERA and 4.73 FIP in 91.2 innings in a swingman role. Instead they’ll stick with a five-man rotation for now while keeping Andrew Painter — a 60-FV prospect who missed all of 2023 and most of ’24 due to a UCL tear and Tommy John surgery — at Triple-A Lehigh Valley. The 22-year-old Painter has been getting knocked around lately, allowing 15 runs in 13.1 innings over his last three starts for Lehigh Valley, raising his season ERA to 5.15 and his FIP to 4.86. Between Lehigh Valley and Low-A Clearwater, he’s throw 92.2 innings so far, and is expected to face an innings cap of around 120.
The Phillies did lose a bit of depth by trading prospect Mick Abel, who had made six starts for the team from mid-May through early July, to the Twins in the Jhoan Duran deal. Speaking of Duran, the team had a scare on Friday when he was carted off the field after being hit on the right ankle by a comebacker. The injury looked scary at the time, as Duran couldn’t put any weight on the ankle, but just 13 hours later he went through his normal pregame routine, and on Sunday, he notched a save by retiring the final two Nationals in the Phillies’ 11-9 victory.
Long story short, even if Wheeler doesn’t require surgery and is merely placed on blood thinners, it’s very possible his season is over. That may be the case for Hader as well. The 31-year-old lefty last pitched on August 8, when he threw a season-high 36 pitches while covering the ninth and 10th innings in a win over the Yankees. On August 11, after Joe Espada called upon Enyel De Los Santos and Bennett Sousa to close out a 7-6 win over the Red Sox, the Astros manager said that Hader had been unavailable due to shoulder discomfort and was undergoing tests. The next day, he was placed on the 15-day injured list with what was initially termed a left shoulder strain, his first major league IL stint except for a COVID-related one in 2021. On August 13, Espada revealed that Hader had gone for a second opinion, and would be out longer than the 15-day minimum. Now we know why.
The Astros announced on Friday that Hader would be shut down from throwing for three weeks, and will be limited to alternating between rest and strengthening exercises during that time. Once he’s cleared to throw again, the pitcher says he’ll need three weeks to ramp up, which would place his return more or less at the start of the postseason — barring any setbacks, of course.
The injury interrupts what has been an excellent season for Hader, who made his sixth All-Star team and has converted 28 out of 29 save chances while pitching to a 2.05 ERA and 3.23 FIP. Relying upon his slider more often than ever — 41.4% of the time, up from last year’s 27.4% — he’s been absolutely dominant. His 36.9% strikeout rate is third among relievers with at least 40 innings, and his .202 BABIP is fifth; he’s not doing it with smoke and mirrors, as both his .158 xBA and 2.04 xERA are dead ringers for his actual stats.
Thanks in part to Hader, the Astros’ bullpen has been one of the game’s strongest. Its 27.1% strikeout rate leads the majors, while its 3.75 ERA ranks 10th and its 3.89 FIP 11th. The team did slide in those rankings on Sunday when five relievers allowed 11 runs to the Orioles in a five-inning span after starter Cristian Javier — making just his second start after returning from Tommy John surgery — departed due to illness. At least outfielder Chas McCormick capped the disasterpiece with a scoreless inning.
The Astros bullpen has thrown just 434 innings, the fifth-lowest total in the majors. That’s rather remarkable given that, due to injuries, just two starters (Hunter Brown and Framber Valdez) have made more than 14 starts for the team, while two (Ronel Blanco and Hayden Wesneski) have been lost to Tommy John surgery, with Spencer Arrighetti additionally missing four months due to a broken thumb and Lance McCullers Jr. now on his third IL stint of the season, at 80 days and counting. McCullers is currently out with a blister, while Brandon Walter is out due to elbow inflammation. Despite that litany, the Astros rotation ranks third in the majors (and tops in the AL) in rotation WAR (11.8) and seventh innings (672), which has taken some of the stress off the bullpen.
That said, the Astros are one of six teams with six different relievers who have made at least 40 appearances, and with one more out from Bennett Sousa, they’d be one of three teams to have five relievers with at least 50 innings, along with the Padres and Reds. For all of their starter injuries, those non-Hader relievers (righties Bryan Abreu and Kaleb Ort, and lefties Sousa, Bryan King, and Steven Okert) are all active and figure to absorb the higher-leverage work, along with De Los Santos, who was recently signed as a free agent and who began his Astros career with a pair of high-leverage appearances. Espada hasn’t named a replacement closer, but so far Sousa (whose four saves are second on the team) and Abreu have notched saves in Hader’s absence, and both King and Okert saved games earlier in the season. With Hader out, just about any of them could get the ball in the ninth.
Losing Hader is a blow, and with the Astros (69-55) holding just a 1 1/2-game lead over the Mariners (68-57), the loss is hardly trivial. For now, the Astros and Hader sound optimistic about an October return, but between their slim division lead and the ticking clock, they have little margin for error.
Content Source: blogs.fangraphs.com