Duke, 31, has pitched in 10 big league seasons with five different clubs, finishing up the 2014 season with the Milwaukee Brewers. He was selected as a starter in the 20th round of the 2001 MLB Draft by the Pirates and worked his way quickly through the minor leagues. Since, he has been converted to a reliever. Duke has posted some up-and-down numbers out of the 'pen, but was strong in 2014.
"Very early on, we identified Zach as one of the best left-handed free agents available this offseason, so we are very pleased he agreed to join the White Sox," said Rick Hahn, White Sox senior vice president and general manager in a press release. "He addresses an important need in our bullpen by giving Robin Ventura a veteran left-handed option late in games."
Duke went 5-1 with a 2.45 ERA in 2014. He pitched 58 2/3 innings last year, striking out 74 and walking just 17. Over his career, he has a 4.46 ERA and a 4.17 FIP (Fielding Independent Pitching) over 1,144 2/3 innings pitched. He has traditionally averaged about two strikeouts per every walk.
A three-year, $15 million deal appears to be a large investment for a lefty reliever that has not enjoyed a ton of success over his career. Regardless, the strikeout numbers were real good for Duke last season, perhaps indicating that he might just be a late bloomer. The White Sox bullpen is currently very young and inexperienced, so Duke will help add some veteran leadership as well.