He's rooting for the Washington Redskins quarterback to succeed in his career, but McNabb's not shy about expressing his disapproval with some of Griffin's life choices in recent months.
"It's too much right now; it's just too much," McNabb said in a candid interview with The Washington Post. "I get some of things he's doing to draw attention to himself: the Adidas commercials, going out and enjoying the life of a young, famous NFL quarterback. I understand RG has a lot of stuff going on.
"But if you're coming off (anterior cruciate ligament) surgery, you don't need to be having a press conference at (organized team activities). Every week? Really? It becomes a circus, a sideshow. It takes away from the focus of what those sessions are supposed to be about: the team."
"So when I look up on TV and see him up there talking all the time about how great he's doing -- or doing jumping jacks or someone else talking about his supernatural healing powers -- I wonder to myself: Is this about selling tickets to the fans or what?
"I don't blame him. They're letting him do it. But at some point, it can be counterproductive. You can set yourself up for more criticism later."
McNabb wasn't done. He questioned Griffin's father for giving an interview in which he explained he wanted to see his son pass more in 2013. McNabb also worried that RG3, coming off extensive knee surgery, is setting lofty expectations that will be difficult to match.
"Especially if Robert doesn't play at first or isn't right for the first eight weeks and it takes a while for him to become the player he was," McNabb said. "So what if you start 2-6 or 3-5? Then everybody wonders what happened, starts thinking, 'But wait, you told us he was great a few months ago. He told us he was great.' "
McNabb seems genuine in his criticism of Griffin. It doesn't come off as a rip-job, rather the thoughts of a man who knows what it's like to be a young star quarterback who's been given the world.
Of course, Griffin has a right to ask why McNabb felt he had to share his opinion in the media. Perhaps that will come up if the two ever sit down together.