Valdez, 26 in March, tossed 20 innings for Arizona this year as a rookie. He also did his second Triple-A stint, posting a 5.90 ERA, 8.5 K/9, 4.5 BB/9, and 1.1 HR/9 in 97 2/3 innings. Heading into the '09 season, Baseball America ranked Valdez seventh among Diamondbacks prospects. They called his changeup "a legitimate plus pitch" and labeled him a potential back-rotation starter.
The Diamondbacks acquired Duke from the Pirates in November after he'd been designated for assignment. I'm guessing the Pirates' return was contingent on the D'Backs hammering out a deal with the arbitration eligible lefty, which they did for a $4.25MM guarantee.