The Orioles completed an instructional camp at their Sarasota, Fla., complex this week that, by most measures, they consider a necessary and resounding success. But it was not immune to the injury bug.

Right-hander Carter Baumler, the club’s No. 18 prospect per MLB Pipeline, underwent Tommy John surgery to replace an ulnar collateral ligament tear Wednesday, according to a source familiar with the situation. The surgery was performed by Dr. Keith Meister in Dallas, Texas, and is expected to sideline Baumler for 12-18 months.

The Orioles’ fifth-round pick in the 2020 Draft, Baumler, 18, signed for an above-slot $1.5 million bonus rather than attend Texas Christian University. He impressed club officials in two instructional camp outings before suffering the injury, reaching 95 mph with his fastball, according to a source. The Des Moines, Iowa, native was considered the state’s best pitching prospect since Pirates righty Mitch Keller and was also recruited to play collegiate football.

That athleticism and upside led the Orioles to complete their unconventional draft strategy in June by targeting Baumler, confident they could lure him away from his commitment to TCU. They did so by signing Baumler for roughly $1 million above the slot value, reappropriating much of the money they saved by signing No. 2 overall pick Heston Kjerstad for a below-slot $5.2 million. Baltimore also used those savings to sign fourth-round pick Coby Mayo for roughly $1.1 million over-slot.

A 6-foot-2, 195-pound righty with three pitches including a potentially plus curve, Baumler was the only pitcher Baltimore drafted in 2020. He is ranked as the seventh-best hurler in the O’s pitching-rich system.

Roster moves
Needing ample space to protect several prospects from the Rule 5 Draft, the Orioles churned their 40-man roster significantly Thursday, outrighting right-handers Kohl Stewart, Branden Kline and David Hess and utility man Andrew Velazquez. Stewart, Kline, Velazquez and Hess all rejected their assignments and became free agents, potentially ending their tenures in the organization.

Hess, 27, was Baltimore’s fifth-round Draft pick in 2014 and debuted in '18, pitching to a 4-20 record and 5.86 ERA in 47 games over parts of the past three seasons. Thirty-three of those appearances came in a starting capacity, with Hess pitching to a 5.79 ERA from the back end of the O’s rotation for much of '18-19. He appeared in just three games in '20, all in relief.

The speedy Velazquez saw time at four positions in 40 games for the Orioles this season, though he hit just .159 without a homer. Stewart, 26, signed a one-year, $800,000 free-agent contract last winter but opted out of the 2020 season, citing his Type 1 Diabetes as an underlying condition. Kline made three relief appearances at the big league level in '20.

The Orioles’ 40-man roster now sits at 33 players, although only temporarily. The club must reinstate Trey Mancini and Richie Martin from the 60-day injured list and decide whether to exercise José Iglesias’ $3.5 million club option by 5 p.m. on Sunday.

Worth noting
The Orioles also announced a series of Minor League re-signings on Thursday, inking catcher Taylor Davis, infielder Ryan Ripken and right-handers Marcos Diplán, Mickey Jannis and Ofelky Peralta to contracts. All were with the organization in 2020, but none appeared at the big league level.

Ripken, 27, is the son of Hall of Fame shortstop Cal Ripken Jr., whose milestone anniversary he helped celebrate this past summer. Jannis, 32, is a knuckleballer, one of the few in the organization. Peralta, 23, turned heads at the O’s instructional camp in Sarasota last month. Diplán, 24, reached Double-A Bowie in 2019. Davis is a former 49th-round Draft pick and viral video star. All profile as organizational depth.