Before Alex Reyes, Carlos Martinez looked to be the elite, flamethrowing prospect in the Cardinals' system. He was dubbed "Little Pedro" by many as he was coming up, boasting an upper-90s fastball and plus-plus curveball. He had a great delivery as well, and the only real concern had about him was his smaller frame.
After spending two seasons in the Cardinals' bullpen due to their incredible pitching depth, Martinez got his first chance at the rotation in 2015, posting a 3.01 ERA in 179.2 innings of work and was named an All-Star. He would earn one more All-Star appearance in 2017 and posted a 3.22 ERA from 2015-2018, mostly as a starter. Injuries really began to bite Martinez in 2018 though, so he made the transition into a bullpen arm for the 2019 season, becoming a pretty good closer for the club.
His return to the rotation in 2020 and 2021 did not go well though, and was not retained by the club following the 2021 season. Martinez has run into some personal and legal issues since his time with the Cardinals, including being suspended 85 games toward the end of the 2022 season.
Like Reyes, no one can blame the Cardinals for betting on an arm like Martinez. For multiple seasons, he actually pitched like the kind of ace the Cardinals are looking for now. But unfortunately, it fell apart for him almost as quickly as his rise was. Even though the club did get some incredible years from Martinez, it's safe to say we all were left wanting more.