St. Louis Cardinals history: The 10 worst first-round picks in the 21st century

4. Third Basemen Zack Cox: 25th pick in the 2010 MLB draft

Here we go again with 2010, Cox was the Cardinals' first of three first-round picks that year, a corner infielder from the University of Arkansas.

Cox did not sign when he was taken by the Dodgers in the 20th round in 2008 and went to Arkansas instead. After he did sign with the Cards he was moving fairly quickly up the farm system, by the end of the 2011 season Cox already made the jump to Double-A after slashing .306/.363/.434 across High-A and Double-A. He was receiving high praise for his early success ranking on Baseball America's top 100 prospects in 2 consecutive seasons, and was ranked as the Cardinals' top hitting prospect.

In 2012, in Cox's second full season with the Cardinals, was playing in Triple A-Memphis, where he hit .254 with 9 home runs and 30 RBI across 84 games. On July 31st, Cox was traded in what was a very shocking move at the time, he was sent to Miami for reliever Edward Mujica in a one-for-one trade. One of the Cardinals' top prospects shipped away for a middle reliever who had a 4.38 ERA in 41 appearances, at the time it was a puzzling move to make, but at the end of the day it paid huge dividends for St. Louis.

Mujica blossomed into a dominant reliever for the Cards in the stretch run of 2012, having an ERA a touch over 1 in 29 appearances, then became an All-Star closer for the Redbirds in 2013, recording 37 saves for that 97-win Cardinals team. Meanwhile, for Cox in the Marlins system, he dealt with some injuries, he hit just .183 in 60 at-bats with the Triple-A team, then was claimed by the Nationals in the Rule 5 Draft in 2015 only to be released shortly after. By 2017, Cox was out of baseball, he ended up not living up to the hype, and the Cardinals ended up greatly benefiting from trading him.

Cox is the second player drafted by the Cardinals in the first round of 2010 to make this list. There is a handful of players that were drafted after Cox that have had solid careers in the major leagues, players like Aaron Sanchez, Noah Syndergaard, Taijuan Walker, and Nicolas Castellanos.