In the time I've been posting around you guys, seldom have I been really down on a prospect that I labelled him a non-factor when others were high on them, and I was wrong! Stewart, Molina, JPA, Gose's bat, Sierra and Musgrove are the examples I can think of (Sanchez to a lesser extent as I never labelled him future bust just questioned his ability to start). There is one example I can think of that I was dead wrong and it wasn't even a case where I had watched the guy pitch. That was Tiny Tim. It's not that I don't like minor league relievers (I love Storen) I just don't like them to be undrafted high school midgets that are max effort.
With Osuna, the body is part of the concern for sure. But also how the TJS has stunted the development. He's still super young but in the past four years he's seen the 6th inning once. BA used to say that despite the bad body he's athletic enough to keep control later into the games...but I didn't see it when he was 18 in Lansing. He was super inconsistent which could be attributed to age and has shown that he gives up solid contact, leading to HR issues. The slider has never been a finished pitch but when will he be allowed to pitch enough innings for it to be a finished pitch. I just see him as a reliever by the end. He might Tiny Tim me...or he'll Nestor Molina the rest of you.
For the record. where you shouldn't listen to me is the guys that I like more than the numbers show or I guarantee to be MVP's like how I was really wrong on Snider, Deck, Cardona, Smith Jr., Hech, Perez, and Handsome Jake (jury is still out)