Posted by Sabrina B. @gametimegirl

Wearing a spiked wig with a black bandana featuring white skulls, an unshaven Brian Cashman, the New York Yankees general manager, rappelled from the side of a 22-story building at dawn Friday.

He had no net, just a safety harness, as Cashman scaled down the side of the 350-foot Landmark building.

“It’s my alter ego,” Cashman said of his look.

Rehearsing for a Sunday holiday event, Cashman took a break from the back-and-forth with Derek Jeter, his late Thursday night negotiations with the agent for Mariano Rivera and his pursuit of Cliff Lee to rappel down the building.

Cashman stayed up much of Thursday night, putting the finishing touches on a new contract for Rivera, but when he arrived in Stamford and saw what he had volunteered to take part in, he admitted to being scared and nervous.

Cashman made a few runs down the building, supported by an experienced rappelling team. He added new gear to his costume. On his second run, he wore deer antlers and looked more confident.

“They’re saying, ‘Go ahead and let go, you’re harnessed,’ ” Cashman said. “But mentally, you don’t want to trust that. Reality doesn’t want to fit what your mind’s telling you.”

Cashman volunteered to take part in Stamford’s “Heights and Lights” event as a celebrity guest elf. He will wear a full elf costume for his jump on Sunday.

By the end of the morning, Cashman looked more relaxed than usual, clearly enjoying the adrenaline rush. This is the 15th year of the event, which has never garnered so much publicity. Stamford Downtown president Sandy Goldstein was delighted by it all.

Goldstein mentioned having Red Sox GM Theo Epstein come down and be an elf with Cashman next year.

“I challenge the GM of the Red Sox,” Goldstein said.

Now, it is back to Cashman’s day job. On a morning he scaled new heights, Cashman said being the GM of the Yankees has prepared him for anything.

On Sunday, he will rappel in front of a huge audience, then hop a jet to the winter meetings in Orlando.

Andrew Marchand