ALEX SPEIER

How baseball teams exchange medical information, and what it means for the Mookie Betts trade

Brusdar Graterol has an extensive injury history, including Tommy John surgery in 2015 and shoulder impingement last season. Emilee Chinn/Getty Images

What does it mean that the deal that would send Mookie Betts and David Price to the Dodgers while bringing back outfielder Alex Verdugo (from the Dodgers) and righthander Brusdar Graterol (from the Twins) to the Red Sox hasn’t been completed after reviewing the medical records?

Given that Graterol had Tommy John surgery in 2015 and had been sidelined for months last season with a shoulder impingement, should any of this come as a surprise to the Red Sox?

To answer those questions, here’s a primer on medical information exchanges with an eye toward the Red Sox’ reported conclusion that Graterol is more likely a reliever than starter after a review of his medical records:

■  How is the medical information exchanged, and how long does it take?

Prior to the completion of trades, teams are aware of the official injured list/disabled list histories of players in the transaction. That information is chronicled in a Major League Baseball database called eBIS (Electronic Baseball Information System).

They’ve also typically researched publicly available information, such as a couple of days missed because of a sore hamstring or a player who has dealt with some soreness in his back, to identify areas of potential concern. Scouts also provide information about player health that might not show up in transactions.

Questions about Brusdar Graterol’s health could present new challenges for Chaim Bloom. Matt York/Associated Press

But it’s only after teams agree to a trade that their trainers make available their organization’s complete files on player medical histories. Those files include MRIs and other images, trainer notes, and virtually every detail about a player’s medical history since his entry into professional baseball — thus offering far more thorough information than is known before a trade agreement.

The files are reviewed by a trainer, who coordinates the sharing of information with other members of a team’s medical staff. Sometimes that means consulting with a team’s head of internal medicine, but more often a team orthopedist will examine specific concerns.

That process occasionally takes a couple of hours — but there are plenty of instances when it might take longer. If a team sees anything concerning — perhaps a question about whether a known condition is more serious than thought — and wants a closer inspection of an MRI or other image, it will typically need to have the files sent on a disc by mail and then reviewed by orthopedists and/or specialists.

That isn’t a turnkey process. After all, orthopedists frequently have previously scheduled workdays that keep them from being able to offer immediate feedback.

Between the transportation of medical files and the need to have them reviewed, it’s not at all uncommon for medical evaluations to take a day or more. So, in a hypothetical case involving Graterol, it’s easy to imagine the Sox looking at the images of his shoulder impingement on Tuesday night, seeing a resulting issue — perhaps associated fraying of the rotator cuff or labrum (again, hypothetical) — and wanting to get a better look.

The file then might have taken much of Wednesday to get into the right hands.

And so, it might not have been until late afternoon or early evening on Wednesday that a determination could be made, based on the scans, that Graterol’s physical condition might be worse than known at the time of the trade. That’s an atypical but not unusual timetable.

■  And so the Sox might suddenly conclude that they’d be comfortable with Graterol as a reliever but not a starter?

That certainly could happen — and in fact does happen quite often. What a team sees in images about a player’s health — how his body responds to the stress of pitching, how it recovers — informs decisions about whether a pitcher should start or relieve.

■  But wasn’t Graterol already a reliever last year?

Yes, but one whom evaluators of multiple teams thought had a chance — based on his pitch mix and how he was throwing at the end of last season — to start.

The 21-year-old hasn’t been durable to this point. Even so, one National League evaluator gave him a 20-30 percent chance to be a mid-rotation starter or better when he heard of the trade. An American League evaluator said that Graterol is a pitcher who should be given every opportunity to start. Another AL evaluator noted the similarities in arm strength and body type to suggest Bartolo Colon as a ceiling for Graterol, albeit with a more likely reliever floor. (It’s worth noting that none of those evaluators ever had access to Graterol’s medical records.)

Brusdar Graterol (right) was part of the Twins’ division clincher last September. Gregory Shamus/Getty Images

In other words, based on the feedback of others in the industry, it’s not unreasonable that the Red Sox traded for Graterol thinking he had a chance — even if limited — to be a starter. And it wouldn’t be unprecedented for the Sox to reassess based on what they saw in his medical file.

■  So, what then?

The Sox likely reached a conclusion about Graterol’s medicals on Wednesday late afternoon or evening — determining that he had a chance to remain valuable as a reliever, but that the chance that he would be a starter had been diminished, perhaps even eliminated. In that case, they’d be trading for a less valuable package of players.

Once that determination was made, the other teams involved in the deal likely would have to make their own assessments as to the accuracy of the Red Sox’ evaluation. So, more orthopedists and more specialists looking at medical files that might have to be physically transferred. The three-team nature of the trade increases the complexity of those dynamics.

At that point, the front offices of the teams could get to work in determining if there was another compensation package — for instance, Verdugo and Graterol plus an additional prospect — that would supply the Sox with their expected return.

■  This all sounds strange. Does this sort of thing really happen?

Not often, but certainly there are instances where trades take days to take from agreement to finality. In 2006, the Red Sox agreed to a nine-player deal with Cleveland that brought Coco Crisp to Boston, but completion of the deal took roughly a week over the medical evaluation of reliever Guillermo Mota. The Red Sox walked away from a trade for Rich Harden at the 2011 trade deadline because of medical concerns. They also had to scrap a three-year, $39 million deal with Mike Napoli after the 2012 season — renegotiating it as a one-year, $5 million deal with $8 million in potential incentives — after discovering a degenerative hip condition.

A 2012 deal involving Mike Napoli and the Red Sox was held up because of medical questions. Matthew J. Lee/Globe Staff

So, in the case of Graterol, the fact that the review of his medical history has held up a deal — one in which he’s the least prominent player — for nearly 48 hours is outside of the normal timetable, but nonetheless within a range of possibilities familiar to all teams.

What it likely won’t mean is a derailment of the deal. Major league sources continue to anticipate that at some point the deal will be consummated — just not necessarily in the form of the original agreement.

Alex Speier can be reached at alex.speier@globe.com. Follow him on Twitter at @alexspeier.

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