I can't think of one. Rocco Baldelli is the closest example I can think of when it comes to a "can't miss" type of elite talent that didn't really pan out. Still, he had two very good years at 21 and 22, got hurt and missed his age 23 season blowing out his knee, but came back to put up another 3.0 WAR season, but then developed a rare disease that ruined his career and he still fought his way back to come up with a couple of huge hits in the ALDS vs the Red Sox, including the game winning hit. Grady Sizemore comes to mind as well - particularly since he burst onto the scene, was expected to be one of the best at his position for a decade, signed an extension that was widely panned as being too team friendly after ~1 MLB season, then suffered a myriad of injuries during what would have been his arbitration years that led to him being a shell of what he was projected to become. I'd argue Orlando Arcia is actually another fair comparison. Always viewed as a plus defender at a premium position, Arcia's 2017 offensive statline during his 1st full big league stint was pretty impressive and quite comparable to Albies' 2018 line minus the power numbers. Arcia put up a 2.5 WAR season as a 22 yr old, and was once considered one of the top 15 prospects in all of baseball, too. Fast forward to present - while still a great defender, I think even the most optimistic of us don't see Orlando becoming a perennial all star anymore. The list of "can't-misses" that never truly realized their potential is really long, for many reasons. It's difficult to come up with, because at one point or another, just about every top 50 MLB prospect that makes it to the majors flashes their talent for long enough a period for people to notice and start projecting just how good they might be if everything goes right. Then baseball inevitably finds a way to to turn 95% of those silver slugger/Cy Young/HOF-potential careers into a mix of good-not-great, meh, and disappointing careers. Albies appears to have all the talent to realize his potential of being one of the best 2B in the game, but let's see how he develops over the next 5 seasons to know whether this contract is the joke for him that it appears to be right now - alot can happen to make the deal overall look well served for both player/team or even make it look player friendly.