White Sox sign left-handed relief pitcher Zach Duke

The White Sox on Tuesday took their first step toward revamping their bullpen by signing left-handed relief pitcher Zach Duke to a three-year, $15 million contract.

Reports indicate Duke, 31, will earn $4.5 million in 2015, $5 million in 2016 and $5.5 million in 2017.

Duke spent the first six years of his career as a starter with the Pittsburgh Pirates. That didn't work out so well for him. He went 45-70 with a 4.54 ERA during those seasons.

He's been with four different teams since 2011, including Milwaukee, where he re-invented himself as a relief pitcher last year. He lowered his arm slot and found success in a LOOGY role. He posted a 2.45 ERA with 74 strikeouts in 58.2 innings for the Brewers in 2014. Opponents batted just .223 against him. More importantly, he limited left-handed hitters to a .198 batting average.

We know White Sox GM Rick Hahn likes relief pitchers who keep the ball on the ground. In that context, the Duke signing is hardly a surprise. The left-hander had a 57.7 percent ground ball rate with Milwaukee last season. Duke also saw a sharp increase in his strikeout totals. He fanned 11.35 men per nine innings in 2014, a huge jump from his career rate of 5.02 per nine innings.

That strikeout rate may not be sustainable, but I think Hahn will be happy with this signing if Duke throws as many ground balls as he did last season with the Brewers.

Is this an overpay? Probably, but that's how it goes in free agency. We live in a day and age where the Toronto Blue Jays gave a soon-to-be-32-year-old catcher in Russell Martin a five-year deal worth $82 million. Heck, the Miami Marlins just gave Giancarlo Stanton $325 million on a 13-year deal.

Most baseball contracts seem ridiculous these days, and you certainly cannot blame the White Sox for anteing up to try to fix their bullpen. The Sox had nothing coming out of their relief corps from the left side in 2014. Donnie Veal and Scott Downs both pitched their way off the roster. Eric Surkamp had a few good moments, but his 4.81 ERA over 24.2 innings didn't inspire enough confidence that he could be the Sox' main left-hander out of the bullpen.

So, the club has opened up its pocketbook a bit to add Duke. I suspect this isn't the last relief pitcher the Sox will sign this offseason. The Sox bullpen was last in all of baseball with 379 strikeouts last year, and the bullpen ERA of 4.38 ranked 14th out of 15 teams in the American League.

Relief pitching has been a real sore spot, and Hahn is making a $15 million bet that Duke can help fix those issues over the next three years.