Peyton Manning said his farewell Monday to the NFL. (Mark J. Rebilas-USA TODAY Sports)

One of the NFL’s greatest-ever players gave one of its most memorable farewell speeches.

“I’ve fought a good fight,” Peyton Manning said Monday at his retirement news conference in Denver. “I’ve finished my football race. And after 18 years, it’s time. God bless all of you. And God bless football.”

Manning was emotional from the moment he began his prepared remarks, his voice cracking as he told a story from early in his NFL career about shaking Johnny Unitas’s hand and being told by the legendary quarterback to stay at it.

“Well, I have stayed at it,” Manning said. “I’ve stayed at it for 18 years…. And today I retire from pro football.”

The day was short on details. Manning revealed little about the particulars of the process that led to him deciding to step away from the sport just after his second career Super Bowl triumph and just shy of his 40th birthday, other than to say the time was right. He revealed even less about his post-playing-career plans, saying he had not eliminated any possibilities.

He was asked about the decades-old allegations against him, from when he was in college, involving a female member of the training staff at Tennessee and did not discuss specifics, saying only that he did not do what he has been accused of doing. Those allegations involve Manning placing his genitals by the face of the female university employee.

Media reports re-examining that incident, plus the report during the just-completed season linking Manning to human growth hormone shipments allegedly sent to his wife, have served to dampen, to some degree, the enthusiasm of the public celebration of the Super Bowl victory last month by Manning and the Broncos. But that wasn’t the focus Monday. The focus on this day was Manning’s goodbye.

There was plenty of feeling, from laughs to near-tears.

“A week before the Super Bowl, our daughter Mosley asked me, ‘Daddy, is this the last game?’ ‘Yes, Mosley, it’s the last game of the season.’ ‘I sure do want you to win that trophy.’ ‘I do, too, Mosley. And that’s what we’re gonna try to do,’ ” Manning said. “Then she asked, ‘Daddy, is this the last game ever?’ And that’s just when I shook my head in amazement because I was thinking Mort [ESPN reporter Chris Mortensen] and Adam Schefter had gotten to my 5-year-old daughter, cultivating a source.”

Manning mentioned that he still holds the NFL’s rookie record for interceptions thrown by a quarterback.

“Every year,” Manning said, “I pull for a rookie quarterback to break that record.”

As great as Manning has been as an NFL ambassador, he also had an edge as a player. He had enough of the jerk factor, for lack of a better term, that all transcendent players must have. Broncos Coach Gary Kubiak provided a glimpse of that Monday when he told a story from this past season about ordering Manning — against Manning’s wishes, Kubiak said — to take a break from playing to get his ailing foot healed.

Manning prepared for his return with private workouts at the team’s facility that Kubiak would have taped and watched later. According to Kubiak, Manning found a unique way to send the message to Kubiak when he felt he was ready to return to the Broncos’ lineup. Always known for his hand gestures at the line of scrimmage, Manning offered one to the camera — and to Kubiak.

“During the workout, he sent me a signal to the film: ‘Hey, we’re number one.’ You could take it that way,” Kubiak said. “I took it as, ‘I’m ready to play, Coach.’ So I was heading home that night. I texted him. I said, ‘Hey, the workout looked great today. And oh, by the way, I got the signal.’ ”

Kubiak said he told Manning he would come by at 9 a.m. the following day to watch the workout. But when Kubiak arrived the next morning at 9, Kubiak said, the workout was done because Manning had rescheduled it to start at 8.

“Before I knew it, the only people left in the bubble were Peyton and I and a bag of footballs,” Kubiak said. “For five minutes, I proceeded to tell him what I thought was going on with our team, where we were at. For the next 25 minutes, Peyton proceeded to tell me where he was, what he thought our team could do and that he was ready to lead our team in that direction. And he was right. He was right.”

The day’s best moments came when Manning spoke seriously, and in a heartfelt manner, about what the game meant to him and how he managed to excel at it.

“I revere football,” he said. “I love the game. So you don’t have to wonder if I’ll miss it. Absolutely. Absolutely, I will.”

Manning reeled off a long list of the things he’ll miss, including his postgame handshakes with his friend and New England Patriots rival, Tom Brady.

“I’ll even miss the Patriot fans in Foxborough,” Manning said. “And they should miss me because they sure did get a lot of wins off of me.”

Manning summed up his record-breaking career as well as it can be summarized.

“There were other players who were more talented,” he said. “But there was no one who could out-prepare me. And because of that, I have no regrets.”

And Manning, of course, had the final word, following the question-and-answer session of his news conference with the word he yelled so often at the line of scrimmage:

“Omaha.”