Fans can watch the pregame ceremony live on mariners.com at 5:30 p.m. PT.
Griffey's No. 24 will be worn by all the Mariners players during batting practice prior to Saturday's 6:40 p.m. PT game against the Angels, but that will be the last time that number is worn by any member of the organization, both at the Major and Minor League levels.
Griffey's jersey will be hung at Safeco Field next to Jackie Robinson's 42, the only number retired throughout all of baseball. And that makes the occasional all the sweeter for Griffey, who is the one who convinced former Commissioner Bud Selig to have every player wear 42 on Jackie Robinson Day.
"It's overwhelming and humbling because of the guy I'm going next to who basically sacrificed his life for guys to play," Griffey said. "It's a weird feeling because what he's done to allow pretty much everyone to play this game and I'm going to be right next to him.
"I don't have a total grasp on it. I'm going to enjoy it. Do I think I'm worth it? Nah, just because of what he's done and what I've done. But it's also an unbelievable honor and something I don't want to take lightly."
Gates will open earlier than normal at 3:40 p.m. PT to allow fans to be in place for the start of the pregame ceremony, which will begin at 5:30 p.m. PT and be shown live on ROOT Sports as well as Mariners.com.
Griffey said he's worn 24 since high school in Cincinnati, when he hit a combined 24 home runs between his prep and summer seasons. From there, the number just seemed right.
What exactly does 24 mean to him?
"How do you describe it?" he said after a long pause. "Everything in baseball is about numbers. But when you look at some of the greatest players who played sports, they wear 24. It wasn't planned, but it was definitely one of the things that when I signed my rookie contract, that was one of the things I asked for, to wear 24. It's extremely important.
"My first apartment in Seattle was 1124. My house number was 24606. So there's a lot of things that have to do with 24. This year, I'll celebrate my 24-year anniversary with Melissa [on Oct. 24]."
Additionally, Griffey was inducted into the National Baseball Hall of Fame on July 24. When Jack O'Connell of the Baseball Writers Association of America called him following his election, the phone rang -- Griffey swears -- 24 minutes after the time he'd been told to await word with his family in their Orlando, Fla., home.
And now that number will hang forever in Safeco Field.
Here are a few other topics Griffey touched on Friday:
• On his return to Seattle the first time while playing for the Reds in 2007: "That first at-bat was one of the greatest feelings I've ever had as a player."
• On his relationship with his kids: "I'm just a normal dad who had an abnormal job."
• On playing with Ichiro Suzuki: "I had a first-row seat to watching one of the greatest baseball players play. The thing about sports, it doesn't matter where you're from. If you can play this sport, you can flat play. And to watch what he's done day-in and day-out is pretty impressive."
• On Edgar Martinez's Hall of Fame candidacy: "He deserves to be in by his sheer numbers and what he's done. He didn't say, 'Hey, I want to be a DH.' He just changed the way that DHs are now producing."
• His thoughts when he was running around the bases after homering in his first at-bat in the Kingdome as a rookie: "Don't fall. I showed video to my kids and they were laughing at me, 'Look at that trot. That was terrible.' I said, 'I hit a few more so I could perfect it.'"
• On his competitive nature: "I hate to lose. I'm really bad at losing. The thing about me is, everybody sees the smile and thinks, 'He doesn't care.' They don't understand the inside of me wanting to absolutely bury somebody when I play. But I don't want to show the emotion. … As far as me wanting to win, that's from Day 1. I wanted to win every game. I wanted to win every at-bat. I wanted to catch every ball. I wanted to throw out every runner. I didn't go out there and say, 'I'm a natural. I'm going to take this week off.'"