"It's six to eight weeks, but it's most probable that he doesn't put a ball in his hand until the start of that timeframe," Virginia head coach Brian O'Connor said. "You never say never, but it doesn't look good for him to throw another pitch for us. It's a rest and recovery thing. He'll end up being fine from a health standpoint, but I know he's really disappointed he won't be able to help the team in the stretch run.
"I love the kid. He kept getting better and better here. He's a great teammate, a great leader. He's everything that we've wanted out of somebody in our program. It's disappointing he won't be able to finish this year like I know he wanted to. He's a Friday night guy in our league for a reason, he's projected to be a pick where he is for a reason. He's a talent and we'll miss his talent, certainly."
Given the timing, it seems unlikely that Kirby will be able to give scouts any more looks at what he can do on the mound. The good news is that after a year and a half as Virginia's Friday night starter in the ultra-competitive ACC, there's a lot of history to study.
"There's certainly enough volume of track record over his career there, the things he's been able to do in one of the premier conferences in one of the premier programs," said one scout who has seen Kirby numerous times. "He's done enough over his two and a half years there to be in the discussion for a premium pick."
There is, of course, a flip side to the argument. Any injury to a pitcher is going to be a concern, and coupled with the fact that numerous reports said Kirby's stuff wasn't as sharp this spring compared to last year, teams will have to put in the work to make sure they are comfortable before using an early pick on the southpaw.
"You start seeing 87 and 88 [mph] this spring, of course you're going to have more concern than if you were throwing with the same stuff last year," the scout said, remembering that Kirby was consistently up to 94 mph a year ago. "There have been flashes of it, but he hasn't been lights out start in and start out like he was in the past. Medical people will have to look at things. Is it related to a shoulder? How close to a tear is the strain? Is this a precursor to something else or a result of his arm action or anything like that?
"You have to do your diligence. He's been a horse, he's taken the ball, but some people aren't going to be comfortable with a guy who has a little hiccup with the medical."
Jonathan Mayo is a reporter for MLBPipeline.com and writes a blog, B3. Follow @JonathanMayoB3 on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.