Daulton Jefferies diagnosed with thoracic outlet syndrome

May 13, 2022; Oakland, California, USA; Oakland Athletics starting pitcher pitcher Daulton Jefferies (66) delivers a pitch against the Los Angeles Angels during the second inning at RingCentral Coliseum. Mandatory Credit: D. Ross Cameron-USA TODAY Sports
May 13, 2022; Oakland, California, USA; Oakland Athletics starting pitcher pitcher Daulton Jefferies (66) delivers a pitch against the Los Angeles Angels during the second inning at RingCentral Coliseum. Mandatory Credit: D. Ross Cameron-USA TODAY Sports

It was clear that Daulton Jefferies was not right. The Oakland A’s young starter had gotten off to an excellent start this season, but had been hammered recently. It was possible that the league had caught up to him in his first extended look in the majors, but those struggles went beyond a need to make adjustments.

The A’s may have received their answer on Friday. Jefferies was diagnosed with thoracic outlet syndrome, explaining the nerve issues he was having in his right arm. He is still looking to get a second opinion, after which the A’s will have a clearer idea as to a timeframe for his return.

Oakland A’s have answer for Daulton Jefferies’ issues

At the start of the season, Jefferies had appeared to be exactly what the A’s had hoped for when he was selected with the 37 overall selection in the 2016 MLB Draft. He had allowed just three runs, two earned, on 12 hits and three walks in his 15.1 innings over his first three starts, striking out nine batters. His 1-2 record was more of a reflection of the A’s offensive woes than his performance.

However, Jefferies has struggled from that point forward. He has allowed 23 runs on 34 hits and five walks in his last 24 innings, striking out 19 batters. The opposition had produced a .324/.351/.495 batting line in their 111 plate appearances over those five outings. It was not a surprise that he lost every one of those games.

Even with this diagnosis, it is impossible to know how long Jefferies will be sidelined for at this point. It all comes down to the second opinion; if the original diagnosis of thoracic outlet syndrome is confirmed, he will be lost for the rest of the year due to the surgery and recovery. Given the track record of pitchers coming back from that procedure, his future would be in question.

Daulton Jefferies has been diagnosed with thoracic outlet syndrome and will get a second opinion. The Oakland A’s now have an answer for his recent struggles.

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