Diamondbacks acquired RHP Jon Rauch from the Nationals for 2B Emilio Bonifacio.
The Diamondbacks get help for their bullpen, but it comes at a steep price: Bonifacio was probably one of their top ten prospects entering the season. He's hitting .302/.348/.387 at Triple-A this season, but is an above-average defender with plenty of speed. Rauch, however, will be under Arizona's control for two more seasons. Luis Ayala, Saul Rivera, and Joel Hanrahan are all candidates to replace Rauch in Washington, with Saul Rivera looking like he might get the first shot with Hanrahan snaring the job down the line.