Brusdar Graterol was in Fort Myers, Fla., on Thursday getting ready for spring training. The question is, which team will he report to next week?

Will he check in Tuesday with Red Sox pitchers and catchers when they report to JetBlue Park at Fenway South? Or will he be 6 miles west at CenturyLink Sports Complex on Wednesday when the Twins begin to arrive at Hammond Stadium?

Graterol, the 21-year old top pitching prospect in the Twins system, remained in limbo Thursday, two days after the late-night blockbuster news that Boston stars Mookie Betts and David Price were heading to the Los Angeles Dodgers in a multi-team trade.

The trade is being held up, major league sources confirmed, because of Boston’s reluctance to pull the trigger after reviewing medical reports on Graterol.

Because nothing is official, the Twins have not yet informed Graterol that he is bound for Boston. The Twins’ return would come from the Dodgers in 31-year-old starting pitcher Kenta Maeda.

After Graterol’s 2016 elbow surgery kept him off the field for 15 months, and a shoulder impingement that sidelined him for two months last summer, the Twins planned to limit the righthander to short bullpen stints, at least in 2020.

But the Red Sox acquired Graterol with the understanding he could return to his lifelong role as a starting pitcher.

“I’ll do whatever is asked of me,” Graterol said at TwinsFest on Jan. 24. “I really enjoyed [relieving]. I learned a lot, and if they give me the opportunity to do it again, that’s what I’ll do.”

As a reliever, Graterol would have less value. It was unclear if Boston was requesting more from the Twins or if they are interesting in paying less to the Dodgers, who are picking up the costly contracts of Betts and Price.

Also unclear was whether the trade could be easily repaired before the weekend.

Betts, the 2018 AL MVP who is due $27 million and will be a free agent after the season, and Price, the 2012 AL Cy Young Award winner, are heading to Los Angeles, with the Red Sox reportedly agreeing to pay half of the remaining $96 million due Price over the next three years. The Dodgers were to send Maeda to Minnesota and outfielder Alex Verdugo to Boston.

Once all teams approve the trade, or any modifications to it, it would be subject to review by Major League Baseball because more than $1 million is involved in the transaction.

Graterol’s elbow surgery was in 2016, when he was 18. He returned in mid-2017 and soon became a dominant starting pitcher in the low minors, with fastball velocity routinely surpassing 100 miles per hour. He reached Class AA last summer but was shut down in May after experiencing shoulder soreness.

When he returned in August, the Twins moved him to the bullpen to limit his workload, then called him up to the majors in September. The native of Venezuela appeared in 10 games, for a total of 9⅔ innings, and struck out 10 while posting a 4.66 ERA.

Twins pitching coach Wes Johnson said in January that Graterol would remain a reliever for the time being, and could make the major league team out of spring training. It seems unlikely the Red Sox were unaware that Graterol probably wouldn’t be able to throw the 200 innings generally expected of a starter in 2020.

“We feel that because it is such a violent delivery, if we can clean up some arm stuff, that’s kind of like Step 1,” Johnson said. “Shorter stints, make sure he’s throwing the right way, and let him get comfortable up here. Right now, I don’t think it would be fair to throw him out there for extended innings.”

The Red Sox, who dumped the salaries of Betts and Price to try to stay under baseball’s luxury tax threshold, don’t have a manager; Alex Cora, who led Boston to the 2018 World Series title, was fired in January after being implicated as a ringleader in the Houston Astros’ sign-stealing investigation when he was a coach for the Astros as they won the World Series in 2017.

Like most of the Twins’ Venezuelan players, Graterol lives in Fort Myers in the offseason because of political unrest back home. He said last spring he hadn’t been back to see his mother in three years.

Staff writer La Velle E. Neal III contributed to this report.