St. Louis Cardinals: Ranking the 10 worst trades in the last 20 years

2. St. Louis Cardinals trade for former first-rounder Khalil Greene.

Cardinals Receive: Khalil Greene

Padres Receive: Mark Worrell, Luke Gregerson

In 2009, the Cardinals were searching for a long-term answer at shortstop, and Greene looked to be a good solution. He had some decent power, although his career average before arriving was an unimpressive .248.

Unfortunately, Greene struggled with social anxiety and had to take time off during the season. When he was playing, it was clear he wasn’t right. In 170 at-bats, he hit only .200 with six home runs. Most of the starts at shortstop that year ended up going to Brendan Ryan.

In another deal where the St. Louis Cardinals gave up a potential future closer, this one stung even more because Gregerson had more staying power than Pérez did. Gregerson became an excellent reliever for the San Diego Padres, as well as with the Oakland Athletics and the Houston Astros.

Before he returned to the Cardinals in 2018, Gregerson had a 3.04 career ERA with 607 strikeouts in 599 innings. He also earned 66 saves with the three teams and served as the Padres’ primary closer in 2015 and 2016.

Worrell, the main piece in the trade, had good minor league stats but never put it together in the bigs. He pitched 5.2 innings with the Cardinals in 2008 and gave up five runs. He spent three years in the minor leagues, then pitched two innings with the Baltimore Orioles in 2011 and gave up eight runs.

Greene’s troubles with social anxiety were exposed with the Cardinals, as he seemed to keep them pretty well under wraps in San Diego. It was an unfortunate deal, as Gregerson could have been an even better option than Pérez to finish games for the Cardinals.