MLB: Spring Training-New York Yankees at New York Mets

Yankees top pitching prospect James Kaprielian has been sidelined since late April with an elbow injury. (Steve Mitchell | USA TODAY Sports)

VIERA, Fla. -- "Wow" was the the first word that popped into Tampa Yankees manager Patrick Osburn's head Wednesday afternoon when he was asked how good prized pitching prospect James Kaprielian was in April.

That good?

Sitting in his dugout on a 100-degree afternoon in Central Florida, Osborn wiped some sweat from his forehead and nodded.

"He was the best pitcher I've seen in this (Class A Florida State) league all year, and it's not even really close," Osborn told NJ Advance Media.

It's a shame for Kaprielian and the Yankees that three starts has been it this season, and that'll probably be it for the 22-year-old right-hander until 2017 due to mid-April elbow soreness that led into some down time and then a setback in late June when the issue was diagnosed as a flexor strain.

Thursday is exactly a month since the Yankees announced the flexor strain for Kaprielian, who is back throwing again at the most primitive stage.

"He's playing catch," Osborn said. "He's not off a mound. I talked to him the other day. He said he's doing all right. He's in his throwing program. As far as his time table and when he's gonna be back on the mound, I don't know."

Osborn is fairly sure that Kaprielian's next game will be next season.

"I would think that this year is probably going to be a wash, but you never now," he said.

Expect the Yankees to play it extra safe with Kaprielian, who was drafted 16th overall in 2015 out of UCLA.

Based on how good he looked in April, Kaprielian could have been a very fast riser through the Yankees' farm system this season, perhaps even pitching his way to the big leagues.

Instead, the Californian now gets in his work with other injured farmhands in Tampa.

"He's with the rehabs, who are separate from our team, so he does all of his work in the morning before we even get on the field," Osborn said.

Before the injury, Kaprielian was dominate in his three starts. In his season debut, he allowed one run over five innings, struck out nine and didn't walk a batter. Five days later, he allowed one hit and three unearned runs over seven innings. His last start was a two-run, six-inning outing in which he again fanned nine without walking anyone.

"Really in those three starts, Kaprielian was on a different level," Osborn said. "I would say the guys that were the closest to him was a kid in Dunedin, Sean Reid-Foley, and our starter (who's now in Double-A Trenton) Chance Adams.

"Kaprielian's raw stuff is premium. You're talking about a fastball that goes up to 96-97 with quality command. He's got two out pitches, his slider and his changeup, and his curveball at times even shows promises of a plus pitch.

"This kid is gonna be something once he gets right."

Randy Miller may be reached at rmiller@njadvancemedia.com. Follow him on Twitter @RandyJMiller. Find NJ.com on Facebook.