Shoemaker’s rehab shut down after pitcher feels discomfort in surgically repaired nerve

Matt Shoemaker’s rehabilitation from a forearm strain ground to a halt on Sunday when the right-hander was shut down indefinitely because of discomfort in the nerve that was surgically repaired last August.

“I’m just extremely frustrated, extremely [ticked] off,” Shoemaker said before Thursday night’s game. “Everything felt great until Sunday, when I ramped up for my bullpen. I felt phenomenal. That’s what’s so frustrating, that it hasn’t gone away yet, that the symptoms came back.”

Shoemaker, who made only 14 starts last season because of a radial nerve compression in the forearm, aggravated the injury in his first regular-season start this season and has been sidelined since.

He worked his way from playing catch to long-toss to throwing off a mound, and he completed his first bullpen session late last week before suffering another setback Sunday.

While an electromyogram (EMG) test on Monday “showed some degree of improved healing in the area,” according to general manager Billy Eppler, the issue is clearly not resolved. Shoemaker will travel to Missouri next week to be examined by a peripheral nerve specialist.

“It’s so hard to predict this,” Eppler said. “Nerve injuries, they’re very fickle, frustrating. They don’t provide you with a lot of answers and a timetable, which is what people want, in everyday life and in athletics.”

Thursday’s news was not good. Nor was it extremely bad. But it extended the state of limbo Shoemaker was in for the first two weeks of April, when he saw numerous medical specialists in an effort to determine the source of his pain.

“Matt is kind of stuck in neutral right now,” manager Mike Scioscia said. “He’s not throwing. We’re still trying to evaluate which direction he’s going to go. It just hasn’t felt the way it should.”

Shoemaker returned from last summer’s surgery to pitch in instructional league last fall, and he reported no problems through spring training. The symptoms he felt during Sunday’s bullpen session were similar to the ones that forced him to the disabled list in early April.

“It’s really hard to put a finger on how you feel emotionally about this besides disappointment, and the person shouldering the biggest disappointment is Matt right now,” Eppler said.

“We’re missing a key part of our rotation, and we’ve had people come in and perform well and step up, which is what you want, what you need, to have happen. But nonetheless, this is frustrating for us and for Matt. Hopefully we will have better news next time.”

On the mend

The Angels were confident the elbow impingement that sent Blake Wood to the DL on April 23 would sideline him for the minimum of 10 days.

But the reliever, who had a 2.31 ERA over 11 2/3 innings in his first 13 games, threw off a mound for the first time Wednesday and will repeat that workout Friday. He could begin a rehab assignment next week.

“We’re definitely moving forward,” Wood said. “I just don’t think you can necessarily put a timetable on things and give an exact date [to return], because that just sets up an expectation that may or may not come true. You don’t want to rush it and have a setback.”

Short hops

Felix Pena, a reliever when he was acquired from the Cubs last October, has been moved to the rotation at triple-A Salt Lake, but not necessarily because the Angels need starting pitching depth in the wake of injuries to JC Ramirez and Shoemaker. “We just thought his stuff profiled as a starter,” Billy Eppler said. Pena, 28, is 0-1 with a 4.50 ERA in six games — five starts — at Salt Lake, with 26 strikeouts and nine walks in 18 innings. … Closer Keynan Middleton (elbow inflammation) was activated off the DL Thursday, and outfielder Jabari Blash was optioned to triple-A.

mike.digiovanna@latimes.com

@MikeDiGiovanna