10. Nick Plummer
The Cardinals drafted Nick Plummer, an advanced high school outfielder, in the first round of the 2015 amateur draft, but he spent only two seasons on Baseball America's top prospects list for the Cardinals, where he ranked eighth in 2016 and 24th in 2017.
Plummer hit .228 and led the Gulf Coast League with 39 walks in his first taste of professional baseball after being drafted, but he later underwent two surgeries on his hand, which knocked him out for the entire 2016 season. Once healthy, Plummer toiled in A-ball for three years, hitting .198 in 2017, .205 in 2018 and .176 in 2019.
The Cardinals decided to let Plummer sink or swim in 2021 by promoting him despite his issues, and he responded with a surprisingly strong season after adjusting his batting stance, hitting .280 with 15 home runs across Double-A and Triple-A. Despite Plummer's breakout, the Cardinals didn't retain his services, and he signed with the New York Mets.
Plummer popped back up in the prospect conversation with the Mets in 2022, earning Baseball America's No. 13 spot for the team, but his cup of coffee with the Mets didn't go well, as he hit just .138 in 31 plate appearances.
Plummer's appearances with the Mets comprised his only major league games in a career that saw a first-round pick who appeared to finally be emerging as a late bloomer fizzle out once again.