The fierce rivalry between the Boston Red Sox and the New York Yankees is so entrenched, it seems a part of baseball’s foundations. When that became literally true, the Yankees took action.

Last summer, a construction worker who is a Red Sox fan buried a Red Sox replica shirt inside the Yankees’ £650-million new stadium, which is being built next to the existing Yankee Stadium and is due for completion in time for the start of next season

“It’s the curse of the Yankees,” a worker told the New York Post last week, claiming suddenly to feel guilty that they had jinxed the club. Maybe so, since the Yankees are bottom of Major League Baseball’s American League East, with six wins and seven losses – though Boston have hardly started the season much better.

Despite denying the story, the Yankees made investigations, and after the shirt was located in a service corridor behind a future restaurant, it took five hours of drilling to find it under two feet of concrete last Saturday. Damaged from the drills, there it was: a jersey bearing the name and number of David Ortiz, the Red Sox’s star slugger. As it happens, Ortiz is mired in a huge slump. Was the curse reversed?

“The first thought was, you know, it’s never a good thing to be buried in cement when you’re in New York,” Randy Levine, the Yankees president, said, apparently referring to the Mafia undertones of the act. He explained the decision to find and expel the shirt: “We decided, why reward somebody who had really bad motives and was trying to do a really bad thing?”

The employee was identified as Gino Castignoli, who lives in the Bronx. He may face criminal charges - if the Yankees can convince the district attorney’s office that burying a replica shirt in concrete is really a crime. The shirt will be donated to a Boston-area cancer charity.

Baseball teams certainly come up with original excuses for their failings. The Red Sox had for decades laboured under the “Curse of the Bambino”. Boston sold Babe Ruth to the Yankees in 1920 and did not win the World Series again until 2004. The Chicago Cubs, meanwhile, are still suffering from the “Billy Goat” curse. Legend has it that in 1945, a fan tried to bring his pet goat into Wrigley Field for a World Series game but it was removed for being too smelly. The goat’s owner cursed the Cubs, and they have not made it to the World Series since.

Could this be the year? The Cubs have enjoyed a steady start in the National League Central. The low-budget Florida Marlins are the surprise leaders in the East, while Joe Torre, the former Yankees manager, has had an indifferent start in charge of the Los Angeles Dodgers, who have lost seven of their first twelve fixtures in the West.

The nightmare continues for the Detroit Tigers. Favourites in the American League Central, they have the worst record in the Major Leagues: played twelve, lost ten, including all six home games. With such a talented line-up, it is starting to look like they’re cursed.