"Oh my God. This one was touching. Emotional," Rivera said. "That's why I love to do this. I get a lot of these things that are motivating. It was different -- in a good way, though."
In the front row, as Rivera told some brief anecdotes from his career and then urged the group to ask their questions, was the family of Luke Brussette -- a 10-year-old killed at a Birmingham, Ala., airport in March by the collapse of a large digital display board showing departures and arrivals.
Wearing Royals gear and wiping their eyes, parents Ryan and Heather were accompanied by three of their surviving children: Joe, 13; Sam, 9; and Tyler, 5, all of whom reside in nearby Overland Park, Kan. Heather is still in a wheelchair from injuries sustained in the accident.
"I was almost in tears seeing the family, the father breaking down and the kids, the wife crying," Rivera said. "This happened not too long ago. But only the strength and the power of the Lord will get you through it. I'll be praying for their family, too."
Rivera said that he was also impacted by the story of high school freshman Jonas Borchert, who recently had Ewing's Sarcoma cancer return.
A rec league pitcher, Borchert told Rivera how he would refuse to stop pitching even while his treatments were under way, lying on the dugout bench each half-inning but insisting upon returning to the mound.
"He'd go out and pitch because the boys were counting on him, and he'd go out and hold his head out on the field," his mother, Kristin, said. "The coach would say, 'Do you want to come sit down?' He'd say, 'Just give me one more batter. One more batter.'"
Rivera thanked him for sharing and, noting his own right knee injury last year in Kansas City, said that he admired Borchert's strength in not giving up. Rivera touched his chest and promised Borchert that he would use his story in the future.
"It was really great," Borchert said. "I've always looked up to pitchers, but I don't think [anyone] as much as Mariano. He's one of the greats, personally to me. I like pitching and it's a great experience."
Rivera mentioned that he was also impressed by the story of Rickey Hernandez, who is in a wheelchair and helped start a baseball league for handicapped children by constructing a diamond in his family's Olathe, Kan., backyard, with help from the Kansas City chapter of the Dream Factory.
"A kid that is in a wheelchair that loves the game but can't play it, he has something done for those that can to make them happy," Rivera marveled.
When Rivera announced his retirement in March, he also revealed his plans for this outreach effort, an idea hatched in recent years with Yankees director of communications Jason Zillo.
Rivera generally spends about a half hour with a group in each city, and expected that he would sign autographs and tell stories while getting a chance to say, 'Thank you.'
But Rivera said that he could never have guessed how much he would be taking from each of these meetings.
"We came up with this idea, but I'll tell you what, it's something that every player should experience because it's wonderful," Rivera said. "The things you get from it, it will change your life.
"There's so much out there that we don't know. Me just saying, 'Thank you,' and appreciating what other people do, these people behind the scenes that we never see and we never know about. Now that I'm seeing them, hopefully many of us do."