MINNEAPOLIS -- When the Twins traded Ben Revere to the Phillies on the last day of the Winter Meetings on Dec. 6, they acquired both a pitcher for the present and one for the future.

The Twins feel like they know what they're getting in right-hander Vance Worley, who has a career 3.50 ERA in 53 big league appearances. But they're banking on upside with right-hander Trevor May.

May reached Double-A for the first time in 2012, and it was a mixed bag for the 23-year-old. On one hand, he kept his impressive strikeout rate going with 151 punchouts in 149 2/3 innings, but he also walked 78 and served up 22 homers to post a career-high 4.87 ERA.

May, though, said he worked through some midseason struggles, as he finished the season with better results, posting a 4.00 ERA in his last eight outings, with 47 strikeouts in 45 innings.

"I started great and I had real high expectations from that first month on, but stumbled a little bit," said May, who had a 2.40 ERA in April. "I look back and think of it as growing pains. I thought I was a much better pitcher at the end of the year, even with the numbers.

"All in all, it was a success. It might not have seemed that way on paper because the stumbling happened for a little bit longer than I would have liked. But I feel like I'm definitely closer to my goal than I was going into last year."

Even with those stumbles, May is regarded as a potential No. 2 starter and is ranked as the club's No. 6 prospect, according to MLB.com.

At 6-foot-5, he's a prototypical power pitcher with a fastball that reaches 95 mph and a 12-6 curveball that has served as his out pitch in the Minors.

But May is working on his circle changeup, which he actually developed before his curveball, and he feels it can add another dimension to his game to keep hitters off balance.

"Having a good curveball is kind of what carried me to where I am, but in Rookie ball guys can hit curveballs and 90-plus-mph fastballs," May said. "So throwing changeups to offset throwing hard is huge. Guys who throw hard and throw good changeups are that much better, and a lot of guys don't. It's not something seen by everyone. I feel like having that makes it that much better."

May will have another top prospect to bounce ideas off of in Spring Training, as he's set to room with right-hander Alex Meyer, who was acquired in the trade that sent Denard Span to the Nationals.

They're both considered a big part of the future for Minnesota's rotation, but Twins manager Ron Gardenhire said it'll be important to monitor them in the spring.

"I just don't want them to try to do too much," Gardenhire said. "The first thing my pitching coach will tell them and I'm going to tell them is, 'Throw it 95, don't try to throw it 105. Do the work, watch, keep your eyes open, your ears open, and keep your mouth shut. Pay attention to the veterans, let them do their thing, and learn.' Then we'll see at the end of Spring Training, when I'm knocking on [general manager Terry Ryan's] door, trying to keep them both."

May, for his part, is planning on heading into Spring Training without any expectations. He's expected to begin in Triple-A Rochester after spending all of '12 in Double-A, but said he hasn't been told anything yet.

"I'm kind of going into it a little blind," May said. "I'm planning on being in the best shape I've ever been in, game ready from Day 1, show where I'm at and all the progress I've made this offseason and compete for a spot, because that's what you're there for. Just kind of see where it goes from there."