When he approached NFL teams, “a lot of them scoffed at it,” Davis recalled.

But not the Buffalo Bills, who played in notoriously bitter weather in winter home games. Jim Kelly, who would become a Hall of Fame quarterback, was one of the first to appreciate it.

“Jim was really the champion of this product,” said Davis, who became business partners with Kelly. “As far as he was a promoter of the product, and so we’ve known each other for all that time. Then, of course, everybody else just started wearing it and it became a standard piece of equipment in the National Football League and that was kind of cool to be, you know, a water boy and coming up and trying to do something and actually coming up with a piece of equipment that now permeates the sport.”

A game-worn and signed Kelly hand warmer from the 1990-91 season recently sold for $2,040.00 on Heritage Auctions.

It all could have made for an awkward moment, or three – the perception that the son of the Raiders owner was helping Raiders opponents.

In December 1988, two days after the Seahawks, then in the AFC West, beat the Raiders in the season finale to win the division and advance to a playoff game at frozen Cincinnati, the younger Davis’ hand warmers arrived in Seattle.

“Just stay toasty, baby,” John Clayton wrote for McClatchy News Services at the time.

In January 1991, days before the Raiders played at Buffalo in the AFC title game, the younger Davis met with Kelly to discuss merchandising plans for The Muff.

And Al Davis was asked (facetiously?) by Doug Krikorian of Knight-Ridder Newspapers, “What do you think of your son consorting with the enemy?”

Davis’ response? “Please, don’t bother me with such stuff.”

Said the younger Davis at the time: “The way I see it, The Muff will help both sides equally. Sure, Jim Kelly will be wearing it, but so will Jay Schroeder. [Bills receiver] James Lofton will be wearing it, but so will [Raiders receiver] Tim Brown. I don’t see where either team will have an advantage.”

The Bo Jackson-less Raiders fell, 51-3.