The Diamondbacks avoided arbitration with Zach Duke by signing the left-hander to a one-year contract with a mutual option for 2012, reports MLB.com's Steve Gilbert. Duke will earn $3.5MM next season (via Gilbert on Twitter), and Nick Piecoro of the Arizona Republic tweets that the mutual option is worth $5.5MM with a $750K buyout. Piecoro adds that if Duke pitches a certain number of innings, the mutual option for 2012 could be worth $7MM. Duke is represented by SFX.
Duke and the team finalized the deal just before yesterday's non-tender deadline, and the left-hander would've in fact been non-tendered had the two sides not come to terms. Arizona acquired Duke in a trade from the Pirates on November 24. As D'Backs GM Kevin Towers tells Gilbert, the club sees Duke as their fifth starter.