It was the perfect place to remember McGregor, 48, who was found dead in his Salt Lake City, Utah, hotel room. The Utah State Medical Examiner's Office is conducting an investigation. Police said the death is consistent with natural causes.
McGregor, a football star at Colorado State who played professionally with several teams, including the Denver Broncos, went on to a successful career in athletic administration. McGregor joined the Rockies in 1993, and developing and completing the project that became Coors Field was his big achievement. McGregor rose to the presidency of the organization on Oct. 18, 2001.
In baseball, McGregor is recognized as an innovator when it came to making the most of business opportunities and developing affordable ticket plans for fans. On Sunday, he was remembered as a family man and friend.
Friends, family members and Rockies employees filled the boxes and grandstands behind home plate. Members of the team mourned from seats behind the home dugout. In addition to black, the predominant color was Rockies purple, a special color for McGregor.
McGregor's four children wore Rockies jersey's with "McGregor 88" on the back. The number is a reference to the one he wore as an All-Century Team tight end at Colorado State. Since McGregor's death, the Rockies have hung a jersey decorated the same way in their dugout.
As the service began, a video made up of snapshots and key moments of McGregor's life, with the Toby Keith song "Cryin' for Me/Waylon's Song" accompanying it, played on the scoreboard in left-center.
The video included footage of McGregor addressing the team's young prospects in January 2007.
"If you come in here and you prepare to be the best baseball player in the world tomorrow, and you have no relationships, what do you have?" McGregor said.
A lifetime of deep relationships was celebrated on Sunday.
"As a friend told me, God needed a president for a little bit more important team," said Todd Tedford, who delivered the welcome.
The opening prayer was delivered by Clint Hurdle. Now serving as the Texas Rangers' hitting coach, Hurdle enjoyed a long career in the Rockies' organization, first as a Minor League instructor, then as a Major League coach and, from April 26, 2002 to May 29, 2009, as the team's manager.
Hurdle also discussed his friendship with McGregor and his family.
Major League Baseball was represented by Laurel Prieb, vice president of western operations and special projects; Joe Garagiola Jr., senior vice president of baseball operations; and John McHale Jr., executive vice president of administration.
Rockies executive vice president of business Greg Feasel -- like McGregor, a former pro football player -- was a close friend and longtime workout partner. Feasel recalled his young daughter Zoie calling McGregor "King Triton," after the kind king in "The Little Mermaid."
"[Rockies manager] Jim Tracy and I don't know if it was when we were talking in the middle of the night or if I saw it on TV, but [Tracy] was talking about [the fact] that Keli was a giant and was bigger than life," Feasel said. "But we all knew what he was talking about.
"Keli was a large man, large in stature. But that's not what Jim was talking about. He wasn't talking about his status, that he was the president of the Colorado Rockies. He was saying he was a giant of a man and a husband and a father and a son. It's not because he played in the NFL. But it was because of who he was."
Onetime Rockies owner Jerry McMorris, who read a scripture passage -- Proverbs 3:5-6 -- said, "Keli's been a big part of our lives. Mary [McMorris' wife] and I see Keli as a son and extended family."
Before the Rockies were born, McGregor was the college roommate of McMorris' son, Michael, who suffered from cystic fibrosis. McGregor spent years working for a cure for the disease.
Sonny Lubick, offensive coordinator during McGregor's career at CSU and later the school's head coach, delivered the eulogy.
"You came to Colorado State as a walk-on without a locker," Lubick said. "Today, I just say your first name, [and] everyone on campus knows the person I'm talking about."
McGregor's four children spoke before participating in a first-pitch ceremony before the game against the Marlins, with Rockies employees and players lined along the foul lines. All of the players rushed out to greet the McGregor family after the pitches were thrown.
McGregor's 12-year-old son Logan handed the lineup card to umpires during the pregame meeting at home plate.
His daughter Jordan, a CSU student, is living in the same dorm her father did.
"Although 12 percent of me feels lost, hurt and confused, 88 percent of me tells me to do what my daddy would do, and from this day forward I made a commitment to him," Jordan said. "I will hold onto every memory we had together."
McGregor's daughter, Landri, said, "What daughter wouldn't feel strong when a 6-8 man of pure muscle mass holds you on his broad shoulders? I am counting on God and my angel daddy to raise me up, so I can walk smoothly through this really rough water."
McGregor's son Logan said, "Mommy says the best compliment anyone could ever give is to say I'm just like you. I love you so much."
McGregor's daughter Taylor read a letter from her mother, Lori. A day before McGregor's death, Lori had completed a video that encompassed their life together. May 31 was to be the couple's 25th wedding anniversary.
"To say my heart is broken, honestly, doesn't even come close," the note read in part. "Honestly, I don't know that I can go on without him. I will, because out of our incredible love for each other, we created four of the most beautiful children in the world, and they need their mother now more than ever."
Rev. Peter Morin, pastor of Faith Lutheran Church, referred to McGregor's values and how they related to running the organization. Morin said McGregor always kept cards in his pocket, to write things Morin said down for future reference.
"[Keli] said, 'You know, Peter, there are 29 losers every year in baseball,'" Morin related. "'Don't get me wrong -- I want to win.' He was a competitive man, for sure.
"But he said, 'If all you're about is winning, it's not really worth it.' It had to be about things that last."
Taylor McGregor concluded the service by directing the fans to look to the center-field fence, where balloons in the Rockies' colors would be released.
"I ask that you can all watch the balloons this afternoon, flying into the Colorado sky," Taylor said. "And as you watch them rise, know that you're watching the spirit of my daddy, Keli Scott McGregor, rise to the kingdom of the man that he loved most, our savior, Jesus Christ."