Tyler O’Neill might have saved a game for the Orioles, but they’ve lost him for an indefinite period.

O’Neill went on the 10-day injured list this afternoon, retroactive to Sunday, with right shoulder inflammation. Infielder Luis Vázquez, who was on the taxi squad, had his contract selected from Triple-A Norfolk.

The injury, which O’Neill described to media in St. Louis as a rotator cuff strain, occurred Saturday when he raced into shallow right field and made a diving catch with two out to rob Tampa Bay’s Richie Palacios and prevent Jonny DeLuca from scoring the tie-breaking run.

The Orioles won 3-2 in 10 innings on Dylan Beavers’ walk-off double.

Suspicion built yesterday that O’Neill had a health issue because he wasn’t in the lineup against Cardinals left-hander Matthew Liberatore. O’Neill underwent an MRI.

This is the latest physical setback for O’Neill, who’s gone on the IL 19 times in his career, including three with the Orioles in 2025. He sustained a concussion on April 9 after passing out at his home due to an illness that caused him to become dizzy.

O’Neill made three stops on the IL last season after signing a three-year, $49.5 million contract with the Orioles. He appeared in only 54 games because of neck inflammation, a left shoulder impingement and right wrist inflammation.

In 85 games this season, O’Neill is batting .212/.300/.377 with eight doubles, 10 home runs and 23 RBIs. He’s posted a 0.5 bWAR, compared to minus-0.6 last season.

O’Neill was 0-for-11 in his last four games after a 6-for-20 stretch over five that raised his average to .223. He hit .286/.318/.691 with five home runs in 17 games in July.

Blaze Alexander’s fractured hand and the Taylor Ward trade to the Mariners presented more opportunities for O’Neill against left-handed pitching, though the Orioles acquired outfielder Christian Franklin from the Nationals. O’Neill brought value coming off the bench, ranking among five players in the majors with at least three pinch-hit home runs.

O’Neill’s three pinch-hit homers are tied for the single-season franchise record with Sam Horn (1991), Jim Dwyer (1986), Pat Kelly (1979), Sam Bowens (1967) and Whitey Herzog (1962).

The Orioles had a possible roster decision to make with Alexander nearing a return from the injured list after playing in his first rehab game last night with Norfolk. He could eventually take O’Neill’s spot.

Alexander is starting in center field tonight in Durham.

The Orioles optioned right-handed hitting Jeremiah Jackson to Norfolk on Aug. 19. They have outfielders Heston Kjerstad and Enrique Bradfield Jr., both left-handed hitters and former first-round draft picks, as possible replacements in Triple-A.

Vázquez appeared in 32 games with the Orioles last season and hit .160/.208/.240 with a double and home run. He’s known more for his defense, especially at shortstop, and he made four scoreless relief appearances over 4 1/3 innings.

Vázquez went 10-for-32 on an injury rehab assignment with High-A Frederick and was batting .225 with four doubles, six homers and a .632 OPS in 50 games with Norfolk. He suffered a broken right thumb after being hit by a pitch in a March 22 exhibition game against the Nationals.

The Orioles have nine players on the injured list with O’Neill’s inclusion today. The 40-man roster is full.

Down on the farm, High-A Frederick right-hander Kyson Witherspoon was placed on the injured list earlier today.

Witherspoon, acquired from the Red Sox in the Adley Rutschman trade, is ranked by MLB Pipeline as the No. 12 prospect in the system. He allowed two earned runs (three total) with 10 walks and 20 strikeouts over 14 1/3 innings in three starts with the Keys. He tossed five hitless innings in his last start.

Update: Witherspoon has a right shoulder impingement.