Nathan Eovaldi likely won’t be throwing another pitch in the majors until 2018.

The Yankees righthander announced Tuesday he’s undergoing Tommy John surgery for the second time. Multiple tests revealed that Eovaldi tore his flexor tendon off the bone and partially tore his UCL. The righthander partially tore his UCL in two spots in high school at age 17.

He said the flexor tendon injury would have been a 3-6 month recovery, but because this is his second UCL surgery, that recovery will likely take 14-18 months.

“It’s a huge blow,” he said. “It’s my second one so it’s a big deal. Hopefully everything goes well with the surgery and I’ll work hard to get back.”

Eovaldi said head team physician Christopher Ahmad would likely perform the surgery.

“Hopefully we will go and get it done as soon as possible and get back,” said Eovaldi, who is eligible for arbitration after this season and can be a free agent after the 2017 season.

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Eovaldi finished 9-8 with 97 strikeouts in 124 2⁄3 innings (21 starts) this season. Despite a career-high ERA (4.76), he had a career-low WHIP (1.31). The 26-year-old went 12-3 with a 4.20 ERA and 1.45 WHIP last season in 27 starts for the Yankees.

Manager Joe Girardi said that rookie righthander Luis Cessa would join the rotation and start Saturday in Anaheim against the Angels.

Eovaldi was removed after the first inning of his Aug. 10 start in Boston. He said he felt he “couldn’t let my fastball go,” but his off-speed pitches felt strong in warmups. Eovaldi said he didn’t feel extra soreness after his previous start Aug. 4 against the Mets.

When Eovaldi suffered two partial UCL tears in high school after throwing a slider, he said it was “by far the worst pain I’ve had” and he felt a tingling sensation from his forearm to elbow.

During his warmups against Boston, Eovaldi said it “just felt a little pinch each time.”

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Eovaldi said doctors told him it’s possible he could return late in the 2017 season out of the bullpen, but even Eovaldi admitted, “It’s pretty much out of the question.” He expects the recovery time to be longer since it’s his second surgery but added, “Then again, last time I had one was nine years ago so it’s a little different.”

Eovaldi said he hasn’t talked to doctors about when he’ll be able to resume his career. Although he’s had Tommy John surgery before, he understands medicine has drastically changed in those nine years.

“It’s a little different just because it’s nine years ago,” he said, “and the first surgery had been done really well considering how hard I’ve thrown and my arm being able to last that long.”