Red Sox shut down pitcher Bryan Mata with what team says is slight ulnar collateral ligament tear

Bryan Mata is generally regarded as the top pitching prospect in the Red Sox organization.Jim Davis/Globe Staff

FORT MYERS, Fla. — Bryan Mata, a 21-year-old righthander generally regarded as the top pitching prospect in the Red Sox organization, has been shut down with what the team is describing as a slight tear in his ulnar collateral ligament.

Manager Alex Cora said Saturday that doctors have prescribed rest and rehabilitation, not Tommy John surgery.

“It’s small enough that I think with treatment he should be fine,” Cora said. “Obviously it’s going to take some time. There’s no timetable.”

Mata signed with the Sox in 2016 out of Venezuela for a modest $25,000 bonus but has since climbed the rankings thanks to his size (6 feet 3 inches, 240 pounds) and the quality of his pitches.

“He’s very important for us,” Cora said. “It’s a tough one. But at the same time we do believe that he’s going to bounce back and he’s going to be OK.”

Mata stayed on his development path to at least some degree last season by pitching in intrasquad games with the reserve group in Pawtucket.

There was hope he could be an option for the major league team at some point this season. That now seems much less likely.

Another top prospect, Triston Casas, is going through the coronavirus screening process to return to camp after spending time in Boston for a medical issue not related to baseball.

“We feel confident that he can join the team over the course of the week,” Cora said. “Things are trending in the right direction.”

The team has provided no other details. But Casas seems out of any danger.

“There’s a lot of people involved in this situation and people are feeling better the last few days,” Cora said. “If you see him join the team that’s a good sign. The fact that he’s here already is a positive step.”

Let’s play two

The Sox and Twins played two innings on Saturday afternoon before the game was canceled by rain. Minnesota had a 2-0 lead in what was scheduled for only five innings.

Ryan Weber pitched both innings for the Sox. He allowed an RBI triple off the center-field wall by JT Riddle in the second inning. Former Sox infielder Tzu-Wei Lin followed with a single.

Twins starter Michael Pineda retired all six batters he faced, striking out four.

Minus 22, plus 19

Hirokazu Sawamura wore No. 22 for a few days but switched to No. 19 once Jackie Bradley Jr. agreed to a deal with Milwaukee. Sawamura wanted 19 to show his respect for Koji Uehara, who wore 19 for the Sox from 2013-16. Uehara endorsed the Sox when Sawamura was a free agent … Franchy Cordero, who was late to camp after testing positive for COVID-19, had his first on-field workout. He’s behind physically but has time to catch up … The Sox have Garrett Richards and Martín Pérez slated for three innings on Sunday. Richards will face the Braves in North Port with Perez pitching an intrasquad game at Fenway South. After Monday’s offday, Nate Eovaldi is scheduled for three innings in an intrasquad game on Tuesday … Righthanded reliever Joel Payamps was claimed off waivers by the Blue Jays. The Sox claimed Payamps off waivers from the Diamondbacks on Nov. 25. He has since been claimed by the Jays (Feb. 10), Sox (Feb. 22), and now the Jays again.