Bids increasing for Rusney Castillo

As the pursuit of Cuban outfielder Rusney Castillo reaches its final days, several clubs told ESPN.com on Wednesday that they believe the Boston Red Sox, Detroit Tigers, Philadelphia Phillies, New York Yankees and San Francisco Giants have emerged as the likely finalists in a rapidly escalating bidding war.

Castillo is expected to choose a team within the next week, according to multiple sources. And clubs involved in the bidding believe he'll ultimately sign a five-year contract in the range of $50 million to $60 million. That would rank as the second-largest deal ever signed by an amateur player from Cuba or any other country, behind only Jose Abreu's six-year, $68 million contract with the Chicago White Sox.

Castillo, 27, has attracted the interest of a number of teams since his defection from Cuba last December. He established residency in Haiti this spring, and held a public workout in Florida last month that was attended by 28 of the 30 major league clubs.

At 5-foot-9, 185 pounds, Castillo isn't a pure masher, in the mold of Abreu or Yoenis Cespedes. But his power/speed combo has drawn comparisons to Andrew McCutchen and Yasiel Puig. And he is viewed as being close enough to the big leagues that a contender that signs him this month could have realistic visions of having him on its roster this October.

Although he played the infield at times in Cuba and took ground balls at shortstop during his workout, his best position is center field, and that's where the teams pursuing him are likely to play him. Because he is older than 23 and played five seasons professionally in Cuba, he is exempt from international signing-bonus pools. He is represented by Jay Z's Roc Nation Sports.