Austin Hayes - the outfielder had a breakout minor league year in 2017, fell back a bit in 2018 and has spent the past couple of years trying to stick in the big leagues for good.
Dakota Hudson - the righthander gave the St. Louis Cardinals another good, young starter to build on besides Jack Flaherty until he needed Tommy John surgery towards the end of the shortened 2020 season.
Sean Reid-Foley - Foley might have been the No. 1 pitching prospect in the Toronto Blue Jays system before the emergence of Nate Pearson as that No. 1 guy in recent seasons.
Parker Markel - I wouldn't have noticed he already made his big league debut in 2019, but the Angels signed him last off-season and I jumped the gun, hoping he would make a big league appearance with the Angels in 2020.
Maybe I was inspired to put this post up when I saw Markel had moved on and was just signed by the San Diego Padres - to show I buy my share of random things for reasons that don't actually play out in reality.