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3/27/2013 5:35 P.M. ET

Twins option reliever Burnett to Triple-A

BRADENTON, Fla. -- The Twins' roster is nearly set, as the club optioned reliever Alex Burnett to Triple-A Rochester on Wednesday, which leaves the club with 25 healthy players in camp.

The roster move officially means the Twins have 28 players in camp, but it also includes injured pitchers Tim Wood, Rafael Perez and Rich Harden.

Of the three, Wood is the only one with a chance to be ready for the start of the season, but it looks like he'll start the year on the 15-day disabled list with a right rotator cuff strain.

"We've got to make a call pretty soon," Twins general manager Terry Ryan said about Wood. "Once we get settled in the next couple days in Fort Myers we'll see where he's at."

If Wood lands on the DL, the Twins roster will be set, as it means left-hander Tyler Robertson beat out Burnett for the final spot in the bullpen.

Burnett struggled this spring with a 7.56 ERA in 8 1/3 innings while Robertson wasn't much better with a 6.75 ERA in 10 2/3 frames.

"It was a tough call," Ryan said. "We had a couple decisions to make there so we decided to go this way. But as is the case every spring, where you start, it doesn't mean you're going to stay there that long. I just told Alex he needs to firm some things up."

The move came as somewhat of a surprise, as Burnett had a 3.52 ERA in 71 2/3 innings with the Twins last season. But he had a 5.08 ERA in the second half of the season and only struck out 36 hitters.

"He had a good first half for us last year, but struggled in the second half and he carried it over into Spring Training a little bit," Twins manager Ron Gardenhire said. "He didn't have many clean innings. We love his arm, but like we've said, we wanted to pick the best guys and he wasn't one of those guys."

So while the roster is coming into clearer focus, Gardenhire said it's still not officially set just yet. The Twins also have to make a corresponding 40-man roster move to add outfielder Wilkin Ramirez to the active roster.

"Things happen," Gardenhire said. "We look like we've got it, but there are some things we still need to straighten out. There are still roster spots we need to make room for. So we'll see how it shakes out. That's why we haven't announced too awful much."

Worley named Twins' Opening Day starter

BRADENTON, Fla. -- Right-hander Vance Worley turned in his best outing of the spring on Wednesday against the Pirates, and was rewarded after the game by being named Minnesota's Opening Day starter.

Twins manager Ron Gardenhire made the announcement that Worley, who gave up two runs on five hits over five innings against the Pirates, will take the mound for the Twins on Monday against the Tigers at Target Field.

But it wasn't exactly a surprise considering Worley has been lined up for that start for the last few weeks, and was the top candidate to make that start with left-hander Scott Diamond on the disabled list to start the season after having a bone chip removed from his elbow in December.

"Worley threw the ball well and he's going to be the Opening Day starter," Gardenhire said. "I thought today he had his best stuff with his breaking ball and all that. So a good day for him."

Worley, who was acquired in the trade that sent Ben Revere to Philadelphia, finished spring with a 5.73 ERA in Grapefruit League play. But Worley said he's satisfied with where he's at heading into the regular season, especially coming off his best start of the spring.

"I'm excited," Worley said. "Especially after the spring I had, I finally got some kinks out and threw the ball well today."

Top prospect Buxton makes spring debut

BRADENTON, Fla. -- Twins outfield prospect Byron Buxton, who was the No. 2 overall pick in last year's First-Year Player Draft, made his Grapefruit League debut on Wednesday against the Pirates.

Buxton, 19, made an immediate impression, singling in his first at-bat against Pirates right-hander A.J. Burnett before stealing second and advancing to third on the throw, which went into center field. He then scored the first run of the game on an RBI groundout from Joe Mauer.

"It was pretty awesome," said Buxton, who went 1-for-4 with a walk, two stolen bases and three runs scored. "The first at-bat, I got it out of the way and just relaxed. I was able to hit the ball and just have a good time."

"He's a stud," Twins manager Ron Gardenhire said. "He's a five-tool guy. He has all the baseball intangibles. So now we just to need to get him some experience."

Buxton, ranked as the No. 19 overall prospect according to MLB.com, coincidentally made his debut against the player he's most compared to in Pirates star Andrew McCutchen.

Twins general manager Terry Ryan said the two players have a similar skill set and so it made sense for Buxton to see McCutchen play in person.

"One of the things we've talked about with him is that he reminds a lot of us of McCutchen,' Ryan said. "So I thought that was ironic. So he'll get a chance to watch McCutchen. It's not like he can't learn from some of our guys like [Aaron] Hicks, but this is an opportunity for him to get some Major League time and at-bats. There is no downside."

Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger This story was not subject to the approval of Major League Baseball or its clubs.