Cris Collinsworth officially replaces John Madden on Sunday, working with Al Michaels on NBC's Buffalo Bills-Tennessee Titans preseason game (8 p.m. ET). And he's not exactly overpromising: "I do consider it the end of an era, not necessarily the beginning of a new era. ... Maybe in few weeks they'll find somebody else."

But Michaels, who worked seven years with Madden, wants to at least give Collinsworth a chance: "I asked Cris to work on his 'booms,' and he's getting there." His next step: mastering POW!

They're kidding. Collinsworth, 50, was on Fox's lead on-air team before joining NBC as lead analyst on Sunday night games. The reason Collinsworth didn't start his new job four years ago: Madden, then at ABC, became available.

Collinsworth stayed high-profile — working cable TV's Inside the NFL, calling NFL Network games, being in NBC's NFL studio and sitting next to Michael Phelps' mom at the Beijing Olympics— until he was "stunned" to hear about Madden's retirement. He says he kept thinking he'd get a call from Madden that it was a joke. Now, Collinsworth sounds humbled: "We would all love to see John Madden sitting right next to Al. ... The treasure that was John Madden's career will be remembered for a long, long time."

Says Michaels on Madden: "John is really a brilliant man. I'm not overstating it. ... He is a Renaissance man."

So we might as well skip ahead to who'll be the guy who'll replace the guy who replaced The Man. Hey, Al, what would you think about Brett Favre in the booth? "I think eventually he will get into broadcasting, and I think he'll be pretty good at it."

Maybe.

But no one, Favre included, is likely to supplant Collinsworth anytime soon. Since he began calling NFL action in 1990, the ex-Cincinnati Bengals wide receiver has been candid, calling out players and coaches before it became fashionable. And like Madden, he avoids treating the NFL as if its scoreboard should use Roman numerals.