Looking back at the Cardinals' 10 most disappointing prospects of the past decade

5. Marco Gonzales

The Cardinals have always liked taking college pitching early in the draft, and they chose southpaw Marco Gonzales with the 13th overall pick in 2013. He ascended the Cardinals system rapidly and debuted in the major leagues just a year after being drafted, reaching the top spot on Baseball America's Cardinals prospects list and 50th in all of baseball in 2015.

Gonzales pitched to a 4.15 ERA in 10 appearances throughout the 2014 season, but injuries would besiege his Cardinals career. He missed time in 2015 with a shoulder injury and then spent all of 2016 on the shelf after undergoing Tommy John surgery.

Gonzales made one start for the Cardinals in 2017, which didn't go well, as he surrendered six hits and five earned runs in 3.1 innings. On July 21, the Cardinals made a one-for-one trade when they sent Gonzales to the Seattle Mariners for outfielder Tyler O'Neill.

With Seattle, Gonzales found his stride. From 2018 to 2021, he had a 3.88 ERA in 582.2 innings, and he led the major leagues with an eye-popping 9.14 strikeout-to-walk ratio during the abridged 2020 season. He was less effective in his last two seasons with the Mariners, and they traded him to the Atlanta Braves in December 2023, who then shipped him to the Pittsburgh Pirates two days later.

Gonzales was rarely fully healthy in St. Louis, which likely played a part in his inability to reach his full potential with the Cardinals. With Seattle, he eventually met most of the expectations that were placed upon him when the Cardinals drafted him.