Philip Humber is becoming quite the AL Central traveling man. After stops in Minnesota and Kansas City, he's now a member of the White Sox (after a brief one month stop with the A's this winter). It's hard to believe, but Humber was once an immensely talented prospect who was the 3rd overall pick in the 2004 draft. Tommy John surgery has long since diminished those skills, but he's hung around and will now be joining his 5th Major League organization.
With White Sox GM Kenny Williams stating that he will have phenom Chris Sale preparing to start this spring (no surprise) Humber will simulataneously provide depth and competition in the starting rotation this spring and could serve in a long relief role in the Sox relatively thin bullpen.
While there can be no doubt that Sale is the odds-on favorite to open the season in the rotation in place of the injured Jake Peavy, it's important to remember that despite his impressive showing in the bullpen at the end of the 2010 season he's yet to make a single professional start. Indeed, the last start he made will have been nearly a year ago. In college.
It's for that reason that Humber was likely brought in. Despite being nothing special himself (there is a reason he's been placed on waivers by so many teams in such a short time frame) Humber is an experienced Minor League veteran with at least some Major League experience who should be able to provide replacement level production. I have no doubt that he could, in a pinch, come in and provide the White Sox with a handful of 'acceptable' starts, giving the team perhaps 20-25 innings of 5.00 ERA ball.
Those innings amost certainly wouldn't be as good as what the Sox would likely get from Sale, but it could buy Sale some important time in Charlotte to refine his craft should that be something the White Sox management felt was necessary. And overall, the likelihood of those innings costing the White Sox more than perhaps a single game over the course of the season is quite minimal.