With the addition of Ervin Santana via free agency, the Twins have essentially sealed up four of five spots in the 2015 rotation. Barring an injury or a dramatic turn of events in spring training, Santana, Phil Hughes, Ricky Nolasco and Kyle Gibson are all going to be there on Opening Day.
That leaves one final opening, with several names in the mix to fill it. Who should be the leading candidate?

Personally, I'm not a fan of the whole "spring training position battle" concept. Deciding who will fill any roster spot -- particularly a rotation spot -- is weighty, and should not be dictated by performance in a couple dozen (or fewer) exhibition games, where the competition ranges from established starters getting their work in to minor-league journeymen.
Going into camp, the Twins need to have a good idea of who they want rounding out the rotation. If they currently have a preference among a list that includes Mike Pelfrey, Tommy Milone, Alex Meyer, Tim Stauffer and others, they haven't been too forward about it.
But for me, there's one clear choice, and that is Trevor May.
May has nothing left to prove in the minors. Last year, he was one of the best starters in the Class-AAA International League, posting a 2.84 ERA, 1.16 WHIP and 94-to-39 K/BB ratio while allowing just four home runs in 98 innings.
It seems silly to send him back there at age 25 after that kind of performance, especially when you consider how many innings May has already logged in the high minors. Between Double-A and Triple-A, the right-hander has made 73 starts; for comparison, Meyer -- who many believe has spent plenty of time in the minors already -- has made 40 starts between those two levels.
One could point to May's unimpressive results during a late-season audition for the Twins, but he pitched better than most people believe.
For instance, you might think May's control was a complete and total mess during his time with the Twins. That was sort of true... in his first start. But after that brutal, jittery debut in which he issued seven walks, the righty handed out 15 free passes in 43 2/3 innings (3.1 BB/9) while throwing strikes at a 65 percent rate, which is league-average.
During that same span, he also notched 44 strikeouts, burning big-league batters with a 92 MPH fastball and quality secondary stuff. He certainy demonstrated that his stuff plays in the majors.
None of that really takes away from the fact that he gave up a ton of hits and a ton of runs, but that's hardly uncharacteristic for a rookie getting his first taste of The Show and learning that some of the pitches he could get away with in the minors aren't going to play. We saw the same thing occur with Gibson, who was crushed in his 2013 call-up before putting together a solid first full season in '14. In many ways, May's debut was more impressive than Gibson's.
When you consider the positive signs May showed last year, and his age, and his lengthy minor-league service, and his potential importance to the future of this rotation, it seems clear to me that he should be first in line to get a crack at that fifth rotation spot. Obviously that changes if he gets hurt or is a total mess in spring training, but the Twins simply have much more to gain from giving May a chance to take hold of that job than they do with someone like Pelfrey or Milone -- both short-term and long-term.
The only question is whether the club is willing to set aside factors like experience and salary in making that decision.