Gold and embedded with four emeralds, the ring is inscribed with his name and number (25).
Patty McDonald said she had been "afraid something like this would happen."
Instead of wearing the ring on his finger - which McDonald said was troublesome when it came to washing his hands - he carried it in a jewelry pouch in his back pocket along with his Pro Football Hall of Fame ring (which is not missing). Frequently, McDonald would bring it out at autograph shows and other events and even allow fans to try it on.
"Some would even have a camera with them and ask if they could take a picture with it," said McDonald, who has always been accommodating with Eagles fans. "And I would always say, 'Sure.' "
Does he think he did that and that someone walked off with it?
McDonald said, "I have no idea what happened to it."
Neither does Patty, who said: "You know how you give something to someone and then you get to talking to someone else. Or it could be that it could have fallen out of his pocket."
Patty said that they noticed the ring was gone a day or so after the party at the restaurant.
"I remember seeing him with the ring and letting somebody look at it," she said. "Then a day or so later, he was looking for it and asked if I had seen it."
She said the ring was an exact replica of the original, which was stolen from a gym locker in the 1970s.
McDonald added, "Life will go on" if he does not recover the ring. In his customarily upbeat way, he said: "I was just glad to even get a chance to play in a championship game."
But he would like to get the ring back and said no questions would be asked if it somehow shows up.