Within today's main post someone made an interesting point; or at least it seemed interesting to me. The poster asked the question (and I paraphrase) "When was the last time the Cardinals were sellers?" I figured that I would take a look at as many trades as I could for as long back as I could handle.
July 26 - Traded Anthony Reyes to Cleveland for Luis Pedermo. Neither buyer nor seller.
January 14 - Traded Scott Rolen to Toronto for Troy Glaus. Neither buyer nor seller.
December 15, 2007 - Traded Jim Edmonds to San Diego for David Freese. Neither buyer nor seller. Seller, if I had to choose one there.
July 31 - Traded Rich Scalamandre to Atlanta for Jorge Sosa. Buyers.
July 30 - Traded Hector Luna to Cleveland for Ronnie Belliard. Buyers.
July 5 - Traded Terry Evans to Anaheim for Jeff Weaver. Buyers.
December 7, 2005 - Traded Ray King to Colorado for Larry Bigbie and Aaron Miles. Neither buyers nor sellers.
August 6 - Traded Jason Burch and PTBNLs (Luis Martinez and Chris Narveson) to Colorado for Larry Walker. Buyers.
March 21 - Traded Matt Duff to Boston for Tony Womack. Buyers.
December 31, 2003 - Traded JD Drew and Eli Marrero to Atlanta for Jason Marquis, Ray King, and Adam Wainwright. Both buyers and sellers.
November 21, 2003 - Traded Tino Martinez to Tampa Bay for PTBNL (John-Paul Davis) and Evan Rust. Sellers. This is the first example I could find going back. Davis and Rust never made the bigs. Martinez went on to put up an .823 OPS for Tampa that year and hit 23 homers and had 20 doubles. This was a salary dump, BUT the big thing here is that it was in the offseason. It still was not a trade deadline dump.
Before that, the next salary dump/sale I could find was trading Dustin Hermanson to Boston for Dustin Brisson, Luis Alfonso Garcia, and Rick Asadoorian. None of them made the majors as well. Again, this was an off-season deal. (December 15th, 2002.)
The most recent trade deadline dump could be July 31, 2001 when we traded Jason Christiansen to San Francisco for Kevin Joseph. Joseph threw 11 innings in 2002, his only major league experience. The next season was his last in professional baseball. Jason Christiansen, at the time of the trade, had thrown 30 games for the Cardinals that season (and 21 the previous season in a partial season with the Cards). He was having a good year with the Birds on the Bat and finished even better with the Giants later.