Bryan Mata, Red Sox’ top pitching prospect, undergoes Tommy John surgery

Red Sox top pitching prospect Bryan Mata underwent Tommy John surgery Tuesday, the team announced Wednesday afternoon.

Mata, 21, suffered a slight tear of the ulnar collateral ligament in his right pitching elbow in early March and recently began a throwing program to determine whether he could avoid the procedure. Once he started throwing on flat ground, it took little time to determine that he could not.

“When he progressed to the stage of throwing the baseball, it became clear pretty quickly that he wasn’t going to be able to progress without some discomfort,” said Red Sox chief baseball officer Chaim Bloom. “At that point, surgery became necessary.

“Any time you have any kind of injury with the UCL, you know that a return is not a sure thing. We were optimistic when we started his progression as he progressed into throwing, but we also knew that if he wasn’t able to go through the throwing program without discomfort that surgery might be necessary.

“The silver lining here is that it didn’t take terribly long to figure that out before the decision was made.

“It’s unfortunate. It’s obviously a lot of down time and a long road back, but we’re going to continue to be able to help Bryan get there.”

This is a tough blow for Mata, who will miss all of 2021 and likely a chunk of next season. Taking into account last year’s minor league season that was lost as a result of COVID-19, that could be nearly three years without game competition for a pitcher who is still developing.

Mata was added to the 40-man roster over the winter, and some in the organization believed he had a chance to reach the big leagues this year on the strength of his mid- to high-90s fastball and slider, offerings he complements with a four-seamer, curve, and changeup.

But even in a best-case scenario, he was unlikely to land on the big league radar until late in 2021. Now, a best-case scenario would be late 2022 for the big leagues, with 2023 a more realistic possibility.

Mata has a career 3.40 ERA in the minors, along with 307 strikeouts in 315 innings. He pitched in the All-Star Futures Game in 2018, and split 2019 between High A Salem and Double A Portland.

Renfroe is heard from

Hunter Renfroe, who belted his first homer of the season in Wednesday’s win, played a key part in the 3-2 victory in Wednesday’s first game. His RBI single in the second inning against Twins starter Kenta Maeda set the tone for the Sox.

He had been hitting .174 in 24 plate appearances going into Wednesday.

When Renfroe signed during the offseason, he said he knew that the Sox were better than their 2020 season indicated. And this year, he and his teammates have a chip on their shoulder.

“We step on that field every day and expect to run the other people off the field,” he said prior to the Sox’ doubleheader sweep of the Twins. “They don’t deserve to be on the field with us. We’re that good.”

Hunter Renfroe rounds third after homering Tuesday.Stacy Bengs/Associated Press

Renfroe came to the Sox widely known for his power, but he has proven to be a plus outfielder, too, patrolling right field.

“I really take my defense seriously,” he said. “I really put pride into what I do and helping the pitchers out as much as possible. I tell them that I’ll run through a brick wall for you. I’ll do whatever I can to help the team win.

“I learned early on that if you’re not playing defense, you’re sitting on the bench. I really worked hard in my early years in San Diego to be the best outfielder I possibly can.”

Barnes is bringing it

Matt Barnes, who had the save in Game 1, has retired 21 of the first 23 batters he has faced this season and has not allowed a hit over seven innings while striking out 14. He has recorded six straight hitless appearances to start the season, the third-longest streak in Sox history.

His four-seam fastball velocity in his first five appearances was identical to his career average (96.3 miles per hour). Yet manager Alex Cora has noted on several occasions that Barnes has more life on the four-seamer and is commanding it better. As a result, Barnes has compiled a 25.4 percent whiff rate on his four-seamer, which doubles his career high set in 2019 (12.7 percent).

Matt Barnes picked up the save in Game 1.Andy Clayton-King/Associated Press

Overall, Barnes has a 30.9 percent swing-and-miss rate on all his pitches, the second-highest rate in the American League. Yankees closer Aroldis Chapman leads with 31.7 percent.

“A lot of competitive pitches,” Cora said of Barnes. “And that’s something we’ve been talking about not only this year, something that we talked about in 2019 in the second half. This is the most aggressive he has been since I managed him.”

Cora hits a mark

The Game 1 victory was No. 200 for Cora as Sox manager. He is the fifth-fastest to 200 in team history, getting there in 335 games. That’s one more than Terry Francona. “It means a lot,” Cora said. “It means a lot in a sense that this organization has given me two chances to be a big league manager. I want to thank everybody who was part of this process: the people in Boston, the Red Sox, and, obviously, my family. It hasn’t been easy. The last 12 months or 15 months. This is not about me, without the players without the organization, I’m not a big league manager.” ... The Red Sox designated righthander Eduard Bazardo as their 27th man before the doubleheader. He pitched the final inning of the second game without allowing a run. He was optioned back to the team’s alternate site. Righthander Colten Brewer originally was a part of the Sox’ taxi squad for this trip and would have been the 27th man, but he didn’t feel good coming out of a recent bullpen and was described as a little banged up.

Twins lose Simmons

The Twins made a series of roster moves. Shortstop Andrelton Simmons, who in March announced his opposition of vaccines, tested positive for COVID-19 and was placed on the injured list. He will miss at least 10 days. JT Riddle was recalled and started at shortstop in Game 1. Outfield prospect Alex Kirilloff was promoted as the 27th man and started in left field in Game 1. Josh Donaldson, who hasn’t played since Opening Day because of a right hamstring strain, was activated for Game 2 and started at third base. Lefthander Brandon Waddell, who pitched two scoreless innings in Game 1, was optioned to make room for Donaldson. The Twins also played the doubleheader without center fielder Byron Buxton, who has a sore hamstring. He hit .469 with a 1.622 OPS through nine games.

Alex Speier and Peter Abraham of the Globe staff contributed to this report.

Julian McWilliams can be reached at julian.mcwilliams@globe.com. Follow him @byJulianMack.