I looked at late season (July and later) trades from 2005 and 2006 in which relief pitchers were traded to contenders. I looked at those two years to judge the likely market. I didn't look at 2007 because there hasn't been enough time to judge those trades...and I just realized Jeff Francis is in town pitching a rehab start at 6:00 and I've gotta' run! I probably missed a few and left out the Kearns trade to avoid that argument for the umpteenth time.
Anyway, do middle relievers bring excellent returns? I'm not so sure.
2005
Kyle Farnsworth traded by Detroit Tigers to Atlanta Braves for Roman Colon and Zach Miner.
RHP Shawn Chacon, Colorado traded to Yankees for RHP Eduardo Sierra, Trenton (AA) and RHP Ramon Ramirez.
RHP Tim Worrell traded by Philly to Arizona for Matt Kata, Tucson (AAA)
Chad Bradford by A's traded to Boston for Jay Payton.
Mike Stanton traded by Washington to Boston for Rhys Taylor, GCL Red Sox (R) and RHP Yader Peralta, Lowell (SS)
2006
LHP Scott Schoeneweis traded to Cincy for 3B/2B Trevor Lawhorn, Sarasota (Hi A)
RHP Jeremy Affeldt, Kansas City and RHP Denny Bautista, Omaha (AAA) to Colorado for 1B Ryan Shealy, Colorado and RHP Scott Dohmann, Colo. Springs (AAA)
LHP Oliver Perez, Indianapolis (AAA) and RHP Roberto Hernandez traded by Pittsburgh to Mets for OF Xavier Nady.
LHP Rheal Cormier traded by Philadelphia to Reds for RHP Justin Germano, Louisville (AAA)
LHP Mike Stanton trade by Washington to Giants for RHP Shairon Martis, Augusta (Lo A)
RHP Elmer Dessens trade by Kansas City to Dodgers for LHP Odalis Perez, Los Angeles (NL), RHP Blake Johnson, Vero Beach (Hi A), and RHP Julio Pimentel, Vero Beach (Hi A)
RHP Mike MacDougal traded by Kansas City to White Sox for LHP Tyler Lumsden, Birmingham (AA) and RHP Daniel Cortes, Kannapolis (Lo A)
RHP Scott Williamson traded by Cubs to Padres for RHP Joel Santo, Fort Wayne (Lo A) and LHP Fabian Jimenez, Fort Wayne (Lo A)
RHP Bob Wickman trade by Cleveland to Braves for C Maximiliano Ramirez, Rome (Lo A)