Mets juggling four candidates for 2B

Who's on second? That's one of the major questions of New York Mets spring training -- although it appears reasonably assured Chin-lung Hu, who was acquired from the Los Angeles Dodgers for minor league left-hander Mike Antonini, is destined for the backup middle infield role, not the second base job.

General manager Sandy Alderson and manager Terry Collins have identified the primary four combatants as Luis Castillo, Brad Emaus, Daniel Murphy and Justin Turner. And there hardly is a lock in that group.

Castillo, 35, is entering the final season of a four-year, $25 million albatross contract. Chief operating officer Jeff Wilpon is on the record saying ownership would sign off on eating the remainder of Castillo's contract ($6 million), or the contract of similarly maligned left-hander Oliver Perez ($12 million), if the new front-office regime requested their releases.

At this point, Castillo will be in spring training, but he may have an uphill battle to remain a Met beyond then. Castillo hit .235 with 17 RBIs in 247 at-bats last season and was benched in favor of rookie Ruben Tejada. (The Mets have resolved to have Tejada open the season as Triple-A Buffalo's shortstop.)

Alderson has acknowledged Castillo essentially has to win the second base job outright because his lack of run-producing ability and lack of versatility in the field would make him ill-suited for a bench role.

"If he's going to be on the club, it probably will have to be as the regular second baseman, or somebody who plays quite a bit of the time at second base," Alderson said. "He just doesn't give us enough coverage other places to play a utility role."

Emaus, 24, will have a supporter in special assistant J.P. Ricciardi, the former general manager of the Toronto Blue Jays. The Mets selected Emaus in the Rule 5 draft at the winter meetings in December for a $50,000 claiming fee. He must remain on the major league roster the entire season to officially become Mets property. Otherwise, Emaus must be exposed to waivers, then be offered back to the Blue Jays for $25,000 if he clears.

Emaus is the prototype for the player the Mets want under Alderson. He showed power last season, with 15 homers in 445 at-bats while splitting time between Double-A New Hampshire and Triple-A Las Vegas, but Emaus also had more walks (81) than strikeouts (69).

Murphy, 25, was poised to be the Opening Day first baseman last season, but he suffered a sprained medial collateral ligament in his right knee during a rundown the final week of the Grapefruit League season. That prompted Murphy to open the season on the disabled list, and for Mike Jacobs and Fernando Tatis to share the early first base duty. By the time Murphy was ready to return, the Jacobs-Tatis platoon had fizzled and Ike Davis had established himself at the position. So Murphy was taken off his rehab assignment and officially optioned to Triple-A Buffalo, to begin learning second base. His tutorial with the Bisons ended June 2 when a takeout slide by a Syracuse player at second base resulted in a tear to the same knee ligament.

Murphy, whose bat is his primary asset, did return in time for the Mets' fall instructional league in Fort Myers, Fla. He then played winter ball with Aguilas, but his time in the Dominican Republic was cut short by a mild hamstring injury. Whether he wins the second base job or not, Murphy very likely will be on the team in some capacity because of his ability to serve as a quality left-handed bat off the bench.

"I've already talked to Murph about it," Collins said. "I said, 'I know you want to win that second-base job. You're going to get that opportunity. But you better be ready to play some first base and some third base, because they're going to need backups also.'"

Turner, 26, may be the longest shot of the group. Whereas Castillo must be cut if he does not make the major league team, and whereas the process of offering Emaus back to the Jays needs to begin if he is not on the squad, Turner has two minor league options remaining. As a result, he can be assigned to Buffalo as insurance without being exposed to waivers.

Turner originally was acquired by the Mets as a waiver claim last May from the Baltimore Orioles. He had eight at-bats for the Mets in 2010 and hit .333 with Triple-A Buffalo. Yet despite going 6-for-6 in the Bisons' finale, during a performance in which he hit for the cycle, Turner was snubbed for a September call-up after rosters expanded.

"It's going to be fun to watch them compete," Collins said.