In February 1980, Al Michaels had not yet established himself as one of the best sports announcers of all time. He had not yet called 20 seasons of "Monday Night Football" or broadcast the NBA Finals.
He was primarily a baseball announcer who had been calling games for ABC for just four years.
But he had called a single hockey game before — ultimately paving the way for Michaels to make one of the most memorable sports calls in history during that year's Winter Olympics in Lake Placid, New York.
"I had done one game and nobody else had done any," Michaels told CNBC on Thursday, two days before the 40th anniversary of the "Miracle on Ice" game.
That is, of course, when the U.S. men's hockey team improbably beat the Soviet Union, 4-3. And it is when Michaels made his famous call — "Do you believe in miracles? Yes!" — as the final seconds ticked down.
"At that particular time, I had no idea this thing would live in perpetuity as long as it has," Michaels said on CNBC's "Halftime Report."
But Michaels' iconic line may not have transpired had the rest of ABC's broadcast team been vaguely familiar with, well, the rules of hockey.
"I'm with the Mount Rushmore of announcers," Michaels said. "We have Howard Cosell, Jim McKay, Chris Schenkel, Keith Jackson, Frank Gifford, Bill Flemming. And somebody had to do hockey in Lake Placid."
Michaels said it was known he had a sliver of experience broadcasting the sport.
"I knew what icing was. I knew what offside was," he said. "And so that's how I got the assignment."
The U.S. team in 1980 was made up of American college hockey players, and its upset of the four-time defending gold medalists took place during the tensions of the Cold War.
It also took place about two weeks after the Soviet Union crushed the U.S.,10-3, in an exhibition match at Madison Square Garden.
After the upset, which Sports Illustrated considers the greatest moment in sports history, the U.S. went on to defeat Finland to win the gold medal. The men's national team has not won a gold medal in hockey since.
Michaels will be in Las Vegas this weekend to commemorate the 40th anniversary of the upset.
He said his memorable, off-the-cuff line "just came from my heart."
"Remember, it was one of the rare times that you can do a game and you know that 99.99% of the audience is going the same way you are in terms of the rooting interest," he said. "And the other 15 people are probably KGB agents, and they're not happy."
When the puck came out near center ice, with a few seconds remaining and the U.S. clinging to a one-goal lead, Michaels said the word that came into his head was "miraculous."
"The way I look at it, I could have been assigned to biathlon," Michaels said. "And there were no miracles on the biathlon course in 1980."
— Disclosure: Al Michaels is the play-by-play announcer for NBC's "Sunday Night Football." Comcast Corp. is the parent company of NBC and CNBC.