Miami Marlins pitching prospect Thomas White has suffered a Grade 1 right oblique strain, sidelining him for three to four weeks during Spring Training. The 21-year-old felt initial discomfort in his Grapefruit League debut against the Toronto Blue Jays. Manager Clayton McCullough noted that the injury was diagnosed the following day.
In Jupiter, Florida, the Marlins announced that their top prospect, Thomas White, sustained the injury after his debut appearance on Thursday. During that 28-pitch outing in the fourth inning against the Blue Jays, White allowed a two-run double to Kazuma Okamoto, issued one walk, and struck out one batter, with a maximum velocity of 96.8 mph. He did not think much of the initial discomfort at the time.
"The next day, kind of the area where he was feeling it, it just presented those symptoms, and that was the diagnosis," McCullough said.
White, ranked as MLB Pipeline’s No. 17 overall prospect and the top lefty pitching prospect, entered big league camp for the first time as a non-roster invitee. Last season, the 21-year-old pitched across three levels: High-A Beloit, Double-A Pensacola, and Triple-A Jacksonville, where he contributed to the Jumbo Shrimp's Triple-A National Championship win. He was projected to start the 2026 season with Jacksonville.
McCullough praised White's maturity despite his youth: "It's easy to forget just how young he is. His talent and performance has -- and rightly so -- got him to a position where he's very close to impacting our team here." The manager added that the timing offers a silver lining, with much of the season ahead, and emphasized getting White healthy.
With Triple-A Jacksonville’s Opening Day on March 27, White might return in time, though rehab starts could be necessary. "It's probably way too early to maybe have an answer on what that build-up [is] and where that will take place," McCullough said.
This injury follows the announcement of core muscle surgery for shortstop prospect Aiva Arquette, MLB Pipeline’s No. 47 overall prospect, who is not in big league camp.