Royals prospect Kyle Zimmer to have surgery to fix thoracic outlet syndrome

Kyle Zimmer threw a pitch during spring training.
Kyle Zimmer threw a pitch during spring training.

There was something wrong with Kyle Zimmer. For months, the Royals knew this to be true. So did Zimmer, the former first-round pick whose career, to this point, has been defined by his time on disabled lists and inside training rooms.

There were good days, sure. There were days when his right arm felt right, and the fastballs popped the mitt, and Royals officials saw the pitcher they envisioned in their starting rotation someday. But then there were other days. There was this dull discomfort and a lingering pain. There was a fastball that couldn’t touch 90 mph.

For months, Zimmer, 24, was a prisoner of the same cruel routine — of shut downs and build-ups, of rehab schedules and setbacks. Nearly every medical test and MRI showed that Zimmer’s elbow and shoulder were structurally sound. But in the mind of J.J. Picollo, the Royals assistant general manager of player personnel, something had to be wrong.

“You’re thinking: ‘Well, it has to be something,’ ” Picollo said.

Royals pitcher Chris Young discusses his recovery from thoracic outlet syndrome surgery in 2013 

For Zimmer and the Royals, clarity came over the last three weeks. After days of testing — and visits to two specialists — Zimmer was diagnosed with thoracic outlet syndrome, a neurogenic issue that is caused by the compression of nerves near the neck and shoulder. He will undergo surgery to address his condition and will not pitch again in 2016.

The injury — which is becoming more commonly diagnosed in baseball pitchers — can result in tingling in the arm or hand. The Royals hope it explains Zimmer’s battles with shoulder fatigue and inconsistent velocity in 2016.

Zimmer is slated to have his surgery in late July or early August, Picollo said. The rehab schedule will last until late November or early December. He is expected to be ready for the start of spring training in 2017.

“We were told it’s 8o to 90 percent that he’ll be back [to full health], which is a very good percentage,” Picollo said. “So we’re optimistic about it. For the kid, you hate that he’s going through something again.”

For Zimmer, it’s the latest setback in a career filled with injury problems. The list is long and well-documented by now. But here is the brief summary: The No. 5 overall pick in 2012, Zimmer underwent an elbow cleanout after his initial summer in the Royals' organization. He strained his latissimus dorsi muscle in 2014 and pitched only 4 2/3 innings. That same year, he dominated hitters in the Arizona Fall League until another shoulder issue surfaced.

The Royals hoped a minor operation to remove damaged tissue from his rotator cuff would grant him a clean bill of health for 2015. But Zimmer experienced another setback in spring training, delaying his start last season. This year, finally, he arrived to spring training ready to showcase himself for a mid-season callup. Instead, he endured more fatigue.

“He had outings where he was excellent,” Picollo said. “The velocity was good, the secondary stuff was good, and then the follow-up outing or two outings later, the velocity would be down. There was a level of discomfort. I don’t think you could categorize it as true pain; it was more discomfort that wasn’t allowing him to let it loose.”

After spending much of April in extended spring training, Zimmer made two appearances for Class AA Wilmington in early May. He then advanced to Class AA Northwest Arkansas, where he made just one start.

In early July, searching for an answer to his discomfort and fatigue, he traveled to Dallas to see Dr. Gregory J. Pearl, a vascular surgeon who specializes in thoracic outlet syndrome.Two weeks later, he received a second opinion from Dr. Robert Thompson, a St. Louis-based specialist who diagnosed Chris Young with thoracic outlet syndrome in 2013. The diagnosis from each doctor matched up.

A few days later, Zimmer phoned Picollo. He was ready to undergo surgery.

“It’s pretty interesting in that we’re unfamiliar with it,” Picollo said. “We haven’t had cases of it. So it’s the first time through for us.”

In recent years, more and more pitchers have been diagnosed with types of thoracic outlet syndrome. Mets starter Matt Harvey was diagnosed earlier this summer. Other pitchers who have dealt with TOS include Josh Beckett, Chris Carpenter, Jaime Garcia, Matt Harrison and Shaun Marcum. For Young, the increase is a result of awareness and more thorough testing.

For now, at least, Zimmer can move forward. The Royals still harbor hopes that he can become a productive major-league pitcher. But as another rehab process begins, the club is poised to be patient once more.

“There’s a relief in that sense, you can point your finger: ‘That’s what that was,’ ” Picollo said. “With Kyle, it’s been very frustrating along the way, because you see the short glimpses of the guy that we know he is, with the good fastball and the breaking stuff and the command. And then you see him come out a couple days later and have a hard time playing catch comfortably.”