SANTO DOMINGO, Dominican Republic -- There are diverse profiles of a winter league player in the Caribbean: Some are young Minor Leaguers trying to raise their stock within their big league organizations, while others are grizzled veterans making a living as year-round ballplayers, spending winters in Latin America and summers in the leagues of Japan, Korea or Mexico.

One of the most common scenarios in winter baseball is that of a prospect who is just getting his feet wet in the Major Leagues and wants to fine-tune his game for the big push for a starting job come Spring Training. Such is the case of the Minnesota Twins' Alexi Casilla, who is making a splash in the Dominican League in 2007-08 with the Cibao Giants.

The Dominican-born infielder is part of a nice group of young players on the Twins, and it's not pure coincidence that Minnesota has traded two of its most established middle infielders -- Luis Castillo and Jason Bartlett -- in the last few months. With the Twins' roster undergoing a significant transition this offseason, Casilla seemingly has a good shot at a starting job at shortstop or second base in 2008. But Casilla refuses to take anything for granted, and with that in mind, he is striving to improve this winter.

"This is a good league to get in shape for Spring Training", said Casilla before a recent Giants game at Santo Domingo's Quisqueya Stadium. "Specifically, I'm trying to improve my hitting from the left side, and on defense, turning the double play [as a second baseman]. But in general I believe in my ability, and the most important thing now is to prepare myself mentally and physically."

As far as the winter leagues go, Casilla believes he's in the right place to get the most out of the experience.

"If you play well here, you're prepared for the competition in the United States. There's a high level of play here," Casilla's manager, Luis Dorante, said. "There's a lot of solid players here from the Majors and Triple-A. You consistently find pitchers who reach the mid-90s [mph], that's for sure."

So far the switch-hitting Casilla has done his part as table-setter in the Giants' lineup. He leads the league with 20 runs scored and 10 steals, and his .304 average and 31 hits put him among league leaders in those categories as well.

On the subject of the 2008 Twins, Casilla tries not to pay too much attention to the trade rumors surrounding ace Johan Santana, but he's certainly aware of how much the team would miss the star left-hander.

"It would be a blow to our pitching, no doubt," said Casilla. "You're talking about a Cy Young winner, a guy who gives you a chance to win every time he goes out there."

"It's not only what he does every five days," Casilla added. "Johan is a charismatic guy in the clubhouse. He really helps the atmosphere on the club."

At the same time, Casilla is aware that baseball is a business and the Twins most likely are entering a new era.

"You have to adjust to the situation and the new reality on the team," he said.

And speaking of new challenges, Casilla has a clear vision of his role on the club next season.

"I want to be a regular," he said. "That's why I'm here."

If Casilla continues to thrive, as he has in the Dominican League, that's all the more confidence he should bring to Spring Training as he looks to become an everyday player.