The Arizona Diamondbacks solidified their bullpen at the cost of depleting their major league rotation, sending Ian Kennedy to the San Diego Padres in exchange for reliever Joe Thatcher, minor league prospect Matt Stites, and a competitive balance draft pick.
Kennedy is the biggest name involved in the deal, and while he's not a superstar (contrary to what his 2011 season might tell you), he's a solid return for a couple of relievers. Kennedy still has two more years of arbitration left, and his flyball tendencies should play out well in Petco Park. His strikeout and walk rates have largely been consistent over his four seasons in the desert, but his breakout 2011 was spurred by a drop in home run rate. Getting him into a place where flyballs go to die like Petco (even with the fences moved in) can only help the 28-year old's career going forth. Kennedy has a 5.23 ERA in 124 innings this season along with 108 strikeouts and 48 walks.
Thatcher is the biggest name heading to the Diamondbacks in return, and he has one year of arbitration left following 2013. He'll slide right into Arizona's bullpen as their lefty specialist, and he's been pure death against them this season, allowing a .212/.257/.231 line over 70 batters faced. For the season, Thatcher has a 2.10 ERA, 29 strikeouts and just four walks in 30 innings. The sole southpaw in Arizona's pen is Tony Sipp, and he has not been at all effective against lefties, allowing a .250/.362/.407 line.
Baseball America ranked Stites as the 27th-best prospect in San Diego's organization coming into the season, and the right-hander has improved his stock with AA San Antonio this year, striking out 51 batters and walking eight in 52 innings. Stites is on the fast track to the majors, and might even get some time in the big leagues in September after being drafted out of the University of Missouri in 2011.
Trading Kennedy makes sense for Arizona due to the surplus the Diamondbacks have in their rotation at the moment. The team has Wade Miley, Pat Corbin, and Randall Delgado all locked in, and Trevor Cahill and Brandon McCarthy are both finishing up rehab stints. The Diamondbacks also have top prospect Tyler Skaggs waiting in the wings at AAA, where he has struck out 87 in 76 innings, but has struggled in seven major league starts in 2013. Arizona also has elite 20-year old starter Archie Bradley at AA, but he might not be ready this year due to some command issues and general growing pains.
Given the weak returns for relievers thusfar, I think the Padres did very well in acquiring a legitimate major league starter in Kennedy while kicking in a prospect to join Thatcher in Arizona. Kennedy is a guy who could thrive in San Diego, and heading back to southern California where he was born and raised could do him a world of good. At the same time, the Diamondbacks traded the correct starter, and are in a great position with their rotation going forward.