In the trade that sent Mulder to the St. Louis Cardinals back in 2004, the A’s acquired pitchers Dan Haren and Kiko Calero and then-minor league prospect Daric Barton.

In retrospect, the deal wasn’t all that bad. In fact, you could call it a definite win for Oakland. Mulder, who was a perennial Cy Young contender in most of his seasons with Oakland, fell apart in St. Louis; Mulder made 32 starts in his first season with the Cardinals, but made only 21 starts over the course of the next three years.

The A’s, meanwhile, got three solid seasons out of Calero and saw Haren develop into an All-Star. Haren, like Mulder before him, was traded to a team in dire need of an ace. The Diamondbacks in exchange for Haren, rewarded the A’s with a slew of prospects. That, however, is a different story. (more…)