(FORTUNE Magazine) - It was as routine a ground-ball out as you'll ever see. Boston Red Sox pitcher Keith Foulke fielded the baseball, took a few steps toward first, and then underhanded it to first baseman Doug Mientkiewicz. But it was no ordinary play--it was the final out of the 2004 World Series, an out that ended an 86-year championship drought.

The ball that made that historic out has become the subject of an off-the-field tussle between Mientkiewicz, who kept it, and the Red Sox, who want it back. The law seems to favor the team. Major League Baseball is backing the Red Sox, and a California court ruled in 2002 that game balls are MLB property until hit into the stands. Mientkiewicz, says University of Tulsa law professor Paul Finkelman, has no more right to the ball than a salesman has to his company laptop. Still, as solid as the Red Sox legal brief may be--the case will be decided by an arbitrator later this year--the team's rationale for seeking the ball reeks of hypocrisy.

The Red Sox insist their case isn't about money, even though the ball could be worth several hundred thousand dollars, according to sports auctioneer David Hunt. It's about their civic duty to Red Sox Nation. "From our perspective, it is very important that an artifact with this much history be part of the club archive and be available for fans to experience," Lucinda Treat, chief legal officer of the Red Sox, told the Boston Globe. Yet when the Red Sox had an opportunity to preserve another important piece of World Series history--Red Sox manager Terry Francona's lineup card from the deciding Game 4--posterity took a backseat to profit. The Red Sox sold the lineup card and other World Series mementos in a December 2004 online auction run by Major League Baseball. "Clearly it's hypocritical," says baseball historian Glenn Stout, co-author of Red Sox Century. "The fact that they'll take other items like the lineup card and sell them for money shows that at some level that's where the interest is."

The winning bid for the lineup card was $165,010, the most ever paid in an MLB auction. The winning bidder was Sky Lucas, a lifelong Sox fan who grew up in New Hampshire. A partner in New York hedge fund firm Vicis Capital, Lucas says he was surprised the lineup card was put up for sale: "For a Red Sox fan, it's a definitive historical document." He says he bought it not so much as an investment--though he would like to sell licensed replicas--but rather to keep it in New England. "I'd like to share it with the rest of Red Sox Nation," he says.

To that end Lucas and his lawyer, David Campbell, approached Sox limited partner Sam Tamposi Jr. and later team management about putting the lineup card on display at Fenway Park. All they asked is that the team insure it while on exhibit. The Red Sox were not interested. (Tamposi and Treat did not respond to repeated requests for comment.) Says Campbell: "I found it odd they would make such a play for the ball yet let this fall through their hands." Mark it down as an error.