Just a few months ago, Brady Aiken was favored to be the first overall pick in the draft, even after the Astros failed to sign him the year prior due to an alleged problem with his UCL. Aiken tore his UCL, and that notion was quickly squashed. There are others, as well: the Duke right-handed pitcher Michael Matuella was rumored to be in the top five, until he also tore his UCL. Kolby Allard, a top left-handed pitching prospect, was put on the shelf with a back injury, and UVA pitching prospect Nate Kirby also missed the end of his season with a lat strain.
Let's start with the obvious: Brady Aiken. Aiken obviously had the issue with the Astros last season, and now he's rehabbing after Tommy John surgery. There were some rumblings that the surgery did not go as planned, so that's probably why teams have tentatively kept him off their boards. But as we also know, Aiken is a big talent. He's a potential ace in the making, and he's just a year past college age. Considering his medicals have not been released and likely won't be until draft time, it's pretty unclear as to when he will go. If his UCL is fine and everything checks out, then he will likely be picked in the top fifteen. But if his future is still shaky, he will definitely be available when the Yankees choose their first pick at 16th overall.
Matuella's situation, on the other hand, is more reminiscent of Jeff Hoffman last year than anything like we've seen with Brady Aiken (Hoffman had Tommy John surgery but was picked ninth overall last year). Michael Matuella also has the ace-type stuff, but most insiders are sure that his surgery went as expected. He's also had back problems in the past year, but many think that that is behind him. He will likely be available for the Yankees, but it would be quite a risk. It's probably less of a risk because this is a higher-floor college pick, so I would certainly prefer him over Brady Aiken based on the Yankees' development profile.
Nate Kirby is yet another top pitching talent in college that has durability question marks, and he too will likely be available. There was a time not too long ago where scouts thought he would be an ace, but I think the industry consensus is that this is a possibly average starter, which I think is fine considering how quickly he could establish himself in he big leagues. This pick, as with the others, comes with the unpredictability of injuries.
Kolby Allard was yet another pitching prospect that could have gone first overall, and Kiley McDaniel had pretty high praise for him not too long ago:
He sits 90-93 and has been as high as 97 mph with a clean delivery, feel for a changeup and an above average to plus breaking ball. Allard is also very young for his class and some SoCal scouts saw shades of Brady Aiken when Allard hit 97 mph late last summer.
Just like with the others, the medicals haven't been released yet so teams have absolutely no idea what type of liability Allard is. So, it really depends on that paperwork; if Allard is fine, he will likely be picked in the top ten, but all signs seem to be pointing towards the middle to the end of the first round. In the likely event he is available when the Yankees pick, I don't see them taking this risk.
The Yankees have made it clear that they are targeting college pitchers and position players, namely Garrett Whitley, Chris Betts, and Tyler Stephenson. If the Yankees did take a chance on one of these injured pitchers, it would be under the condition that they are getting a player that can successfully rehab, one that fits their development strengths, and with the assumption that they are signing under-slot so they could save money for the rest of the draft. That rules out both Kolby Allard and Brady Aiken, and leaves Allard and Matuella. But if the Yankees feel that both of those will not be consistently healthy, then look for the scouting department to target high school position players and healthy college pitchers.