The Arizona Diamondbacks can hardly complain about Trevor Cahill after the right-hander pitched a shutout in his last start.
They're probably feeling at least a little regret, however, about what they gave up to get him.
Cahill and red-hot Oakland Athletics rookie Jarrod Parker square off Saturday night at Chase Field in an intriguing matchup of pitchers who were traded for each other six months ago.
"It's cool how it worked out," Parker told the Diamondbacks' official website. "This is what everyone wants to see, right?"
After winning the NL West last year, Arizona was in "go-for-it mode to stay on top of the division," according to general manager Kevin Towers. He tried to bolster the staff immediately by acquiring Cahill, an All-Star for the A's in 2010.
Oakland, meanwhile, saw an opportunity to add an elite pitching prospect, sending Cahill and reliever Craig Breslow to the Diamondbacks for Parker, outfielder Collin Cowgill and reliever Ryan Cook on Dec. 9.
Parker (2-2, 2....