Transcript for Showdown Between Two of Football's Greatest Quarterbacks
the big showdown between two of football eagle biggest quarterbacks. Peyton manning and tom brady. As a lot of fans are cheering, they will be trying to crack a secret code. Why did peyton manning of the broncos keep shout one word "omaha." Here's abc's john donvan. Reporter: A battle of titans it'll be this sunday. Denver's hopes resting on peyton manning. Boston marching behind tom brady. And then, there's omaha, nebraska, with no direct stake in the game except this. Omaha, omaha. Reporter: That's the voice of the storied peyton manning. Omaha. Reporter: During last sunday's playoff win against san diego, more than 40 times the word came out of his mouth. I've had a lot of people ask it's a run play, but it could be a pass play or a play-action pass depending on a couple of things the wind. Yes, the jerseys that we're wearing, so it's varies. Reporter: Yes, it's a tactical code word. Football has a lot of them. But, in omaha, america's 43rd largest city, at last count, they're loving the attention. Like the boys and girls at benson high. And the seven omaha businesses who have promised to give 100 bucks this weekend each and every time mac yells the magic word. Which last weekend would have added up to $30,000. And omaha stakes. Game-winning secret code. Three short sill billions. Sorry, you other nice cities, four syllables don't cut it. John donvan, abc news, washington. And a milestone birthday today and you probably know who's. Do you recognize this little
This transcript has been automatically generated and may not be 100% accurate.