On Monday afternoon, Jim Harbaugh tweeted out a photo of him with Willie Mays.
So how did the 49ers' former head coach meet the Hall of Famer?
"Just went and knocked on the door," Harbaugh said on KNBR 680 on Friday morning. "Yep. And Willie's wife was there and opened the door and said, 'It's the coach!' Couldn't have felt any better...
"... Willie gave me a jersey and signed a bat. I know a lot of people argue about it, but I've always said I think Willie Mays is the greatest baseball player to ever play. He's the five-tool player. You look for that in football players. He's the platinum of athletes, especially football players.
"You love being around the highest evolution of human beings. That's Willie Mays."
Over the course of Harbaugh's four-year tenure with the 49ers, he mentioned Mays several times.
In December 2013, Harbaugh compared Seahawks safety Earl Thomas to Mays.
Back in October 2012, Mays visited 49ers practice. But that didn't compare to this week's time together.
"Willie Mays, I would drive by his house every day to work when I was going to the 49ers," Harbaugh reminisced on Friday. "I Just wanted 10 minutes, I just wanted to stop by and spend 10 minutes with Willie. I got to spend an hour. It's like dying and going to heaven. The Say Hey Kid. He's the best.
"And what a wonderful guy ... got to talk a little baseball, talk football with him. He followed our team this year. That was really neat."
Feel like I've died & gone to heaven. Spending time with baseball's greatest player & my friend, Willie Mays. pic.twitter.com/bpASfYHCTI— Coach Harbaugh (@CoachJim4UM) February 8, 2016