Updated

By Daniel Trotta

NEW YORK (Reuters) - No matter what happens to the New York Yankees in the 2010 playoffs, they know a formidable decision awaits them in the off-season: What to do about Derek Jeter's contract.

The Yankees' marquee player and team captain just had his worst season at the worst time for him considering that he is about to become a free agent and at an age, 36, when a baseball player, especially a shortstop, can be expected to decline.

First comes the best-of-seven American League Championship Series in which Jeter's Yankees play the Texas Rangers starting on Friday, with the winner going on to face the National League champion in the World Series.

After that, Jeter's 10-year, $189 million contract expires.

The Yankees cannot treat him as an ordinary player and apply normal market conditions, meaning they are likely to pay a premium to retain the face of the storied franchise. Experts say he would be worth $10 million per season at most if he played for any other team.

Jeter could increase his value with an exceptional performance in the remainder of the playoffs, especially if the Yankees win an unprecedented 28th World Series.

"Jeter is more valuable in New York than anywhere else. Jeter and the Yankees go together. The Yankees make more money because Jeter is on their team. Jeter is more likable to fans because he's on the Yankees. So they have a strong incentive to work this out," J.C. Bradbury, whose new book "Hot Stove Economics" attempts to determine how much players are worth, told Reuters.

"Jeter has made over $200 million in his career, so a lot of this is about saving face. He doesn't want the Yankees to slap him in the face with an offer that he perceives to be unfair. He'll just go elsewhere," Bradbury said.

Bradbury said a nameless player of Jeter's age and statistics would be worth $9 million to $10 per year on the open market, but figured Jeter should easily sign for $12 million to $15 million per season.

Joe Sheehan of Baseball Prospectus, a website specializing in advanced metrics for the sport, put the value of a Jeter-like player at $15 million to $16 million for two years -- or possibly $30 million for three years based on his intrinsic value -- but guesses he will sign for something like $64 million for four years.

The Yankees have the money. Forbes magazine estimates the club is worth $1.6 billion, with the Yankees brand alone accounting for $328 million of that.

DEFENSIVE QUESTIONS

The tricky part is how to handle his defensive assignment. Shortstop may be the most important position on the field, and much of Jeter's status comes from playing it.

"The issue of shortstop is not going to go away," Sheehan said. "In his prime he was a good, not great, shortstop. Right now he is below average."

While Jeter boasts a spectacular collection of defensive highlights, many of them in important, pressure-packed games, the advanced defensive metrics that the clubs use to evaluate players show he is far from worthy of his Gold Glove reputation. But even critics of his defense say he more than makes up for it on offense -- at least until this year.

Jeter is coming off career lows in batting average (.270), on-base percentage (.340) and slugging percentage (.370) compared to his Hall of Fame-worthy lifetime numbers of .314/.385/.452 over 16 seasons.

Unless he returns to form, he does not project as an ideal fit for a less demanding defensive position such as the outfield, and the two corner infield positions are filled with the long-term contracts of sluggers Alex Rodriguez and Mark Teixeira.

Jeter was unavailable to speak to the media after a team workout at Yankee Stadium on Wednesday, but his manager, Joe Girardi, assured that Jeter would not be distracted by his subpar season and try to make up for it during the playoffs.

"That's where players get in trouble when you try to do that," Girardi said. "He had a very good month of September, I thought, and he's had a good October. I just feel that Derek's being Derek."

(Editing by Steve Ginsburg)