4 deft trade deadline moves by Cardinals' John Mozeliak and 1 dismal one

The Cardinals acquiring Matt Holliday for prospects that never panned out was a great trade.

Cardinals trade: Brett Wallace, Clayton Mortenson, Shane Peterson, and $1.5 million
Oakland Athletics trade: Matt Holliday

At the time, this deal made sense for the short term. The Cardinals received one of the game's best outfielders at the time for the remainder of the season. However, Brett Wallace was the #40 prospect that year according to Baseball America, Mortenson was a top-10 prospect in the organization, and the Cardinals had just chosen Peterson in the second round of the 2008 draft.

This was a risky trade, but it was necessary. Holliday slotted himself into the middle of the lineup, and he was an offensive force to add to Albert Pujols and Yadier Molina. While Holliday's defense was nothing special, he still provided a huge boost to the team.

Brett Wallace and Clayton Mortenson saw some time in the majors, but never panned out to be much, and Shane Peterson never saw 10 plate appearances in the majors until 2015. He accumulated a total of 0.3 fWAR in 125 major league games.

The primary risk with trading for Holliday was the fact that he was going to be a free agent at the end of the year. Even if the prospects traded ended up being league-average guys, they still would have provided more value long-term than Holliday would for the Cardinals without an extension. John Mozeliak saw this concern and immediately worked on inking Holliday long-term.

That extension came to fruition, and the Cardinals locked up their corner outfielder for the future for 7 more years. This was a masterful trade done by John Mozeliak at the 2009 trade deadline. He traded prospects for a star, and it worked out quite well for the team.