Pasadena, Calif. • When Ken Jennings was invited to participate in the “Jeopardy!: Greatest of All Time” tournament, he replied quickly. He told the producers no.

Partly because, he admitted, he was a concerned that he might tarnish his reputation as a “Jeopardy!” genius if he didn't do well.

“I’m a little older. I’m a little slower,” Jennings told The Salt Lake Tribune. “I don’t remember names in that five seconds that [host Alex] Trebek’s glaring at you. It’s getting a little harder at my age.” (He’s 45, by the way.)

And he wasn’t real happy about the timing of production. The ABC event was taped shortly before the end of 2019.

“I was just thinking, You’re going to tape it when? Around Christmas? So, what, I’ve got to spend the whole holidays worrying about ‘Jeopardy!’?” said Jennings. “You know what? I don’t want to.”

But what convinced him to return was the chance to appear — maybe for the last time — with 79-year-old Trebek, who’s talking about retirement and undergoing treatment for pancreatic cancer.

“Just the idea that you’ve got a chance to be associated with your favorite show one more time — kind of a capstone of Alex’s career — you don’t want to screw around with that,” said Jennings, a BYU graduate who lived in Salt Lake City when he made his amazing “Jeopardy!” run in 2004. He won 74 days in a row, amassing $2,522,700.

(He moved his family back to the Seattle area, where he grew up, in 2006. “But we still go back all the time,” Jennings said. “We still have family there. We take the kids there a couple times a year. We still love Salt Lake and we miss a lot of things about it.”)

And, he finally decided, the chance to join in the “fun” on “Jeopardy!” again was something he just had to do. “Once you’ve had that adrenaline rush — once you’ve played ‘Jeopardy!’ against the smartest people — you don’t want to turn that down.”

(Eric McCandless | ABC via AP) Host Alex Trebec, left, appears with contestants James Holzhauer, Ken Jennings and Brad Rutter, from left, on the set of "Jeopardy! The Greatest of All Time" in Los Angeles.

Jennings is competing against Brad Rutter, who won the most money on “Jeopardy!” ($4,688,436) and has never lost to a human opponent, and James Holzhauer, who recorded the top 15 single-day winnings and totaled $2,712,216. The first of them to win three matches wins $1 million; the two runners-up each get $250,000.

Jennings is two-thirds of the way to the million bucks. He won on Tuesday and Thursday; Holzhaur won on Wednesday; Rutter has been shut out so far. The competition continues next Tuesday, Wednesday and Thursday at 7 p.m. on ABC/Ch. 4 — until somebody wins three times.

Returning for “Greatest of All Time” proved to be “a very poignant experience” for Jennings because of Trebek’s battle against cancer.

“I’ve been listening to him my whole life,” Jennings said. “Even now, just hearing that voice, it reminds me of being a kid, running home to watch ‘Jeopardy!’ when I was 10 years old. It reminds me of standing behind that podium and scrambling to come up with an answer. A lot of the cadence of my life is that voice.

“And just being associated with my favorite show and my favorite host in some small way has been the greatest honor in my life.”

So he decided to put his anxieties aside and compete once again.

“I was getting stressed about this tournament, and I thought, You know what? Just enjoy it,” Jennings said. “It might be the last time you’re up there with Alex. The last time you’re up there with Brad. You may never be in that sound stage again. Just enjoy every second. And I really tried to do that.”

He did admit that he had another reason for agreeing to compete.

“I guess another reason I come back is that I keep losing to Brad Rutter,” he said with mock annoyance. “Every time I’m invited for a tournament, I’m excited. I make the finals. And I finish second.”

He finished second to Rutter in the 2005 “Tournament of Champions,” the 2014 “Battle of the Decades” and the 2019 “All-Star Games.” Jennings also finished second to the Watson computer in the 2011 “IBM Challenge,” but he did beat third-place Rutter. Jennings and Rutter are tough competitors, but they’ve also been through a “weird bonding experience.”

“You’re playing against each other for a seven-figure check. But, at the same time, you’re the only people in the world who know what it’s like to do that at that level,” Jennings said. “It’s like the NFL guys slapping each other on the ass, except we don’t do as much of that.”