PHOENIX — The news of Rob Gronkowski's retirement announcement reverberated around the NFL annual meeting here Sunday afternoon, eliciting any number of reactions to his epic and memorable nine-year NFL career in New England.

Outside of Deion "Primetime'' Sanders, has there ever been any player who managed to meld their elite talent and the one-of-a-kind persona they created better than Gronk? Rarely does the image and the reality meet as perfectly as it did with the Patriots' star tight end.

"That's true and the other thing is he truly embraced who he was and always had a lot of fun with it,'' NBC Sunday Night Football play-by-play man Al Michaels said. "Of course he has the perfect name. His name wasn't Smith. It's Gronkowski, and it's Gronk. He was a real character and he'll be missed in the game.

"A heck of a player, that's for sure. And a lot of fun to watch. Not only a star player, but entertaining. Your eyes were always on him, and at his best, he was terrific. Frankly I'm glad he had as long a career as he did, because I know what he's been through. You come off those back surgeries, and to be able to do what he did, I thought it was tremendous.''

Veteran Baltimore head coach John Harbaugh and his Ravens had their fair share of success in defending Gronkowski, but that doesn't mean Harbaugh necessarily wanted to see Gronk return for a 10th NFL season in 2019.

"Gronk retired?'' Harbaugh said. "I'm happy. I'm thrilled. Good for him. I think it's going to be great. He's ready for the next phase of his life and I think he's going to do great.

"But seriously, seriously the guy did it all. He blocked, you couldn't tackle him, he was a hard guy to cover. He just changed the math. He changed the math. He was just a nightmare to try and defend.''

In his most dominating prime, Gronkowski was the X factor that could never be completely schemed for, Harbaugh said.

"Especially when you put him with guys like (Julian) Edelman or (Tom) Brady,'' Harbaugh said. "The fact that when he gets one step, who can cover the guy? You want to play zone? You want to play man? He's blocking people. There's really no answer for him. We did have a little success at times and we were able to defend him occasionally, but….''

Asked his favorite memory of facing off against Gronkowski, either in success or failure, Harbaugh laughed and began talking about a controversial chapter in Baltimore's 35-31 loss in the 2015 AFC Divisional round playoff game at Gillette. Harbaugh accused the Patriots of using "illegal'' formations during the game, when New England in the third quarter utilized a novel and confusing blocking scheme that featured only four offensive linemen. Brady in the post-game fired off a memorable line aimed in Harbaugh's direction, suggesting the Ravens and their coach "study the rulebook.''

"(One memory), but I don't want to talk about it though because they'll call me a big baby,'' Harbaugh said with a smile. "I remember when they put the five receivers out there, and you didn't know who was eligible and they ran (Gronkowski) up the seam. I'll never forget that.

"Learn the rules! And I was like, 'Oh, I know the rules. That's a palpably unfair act. Thanks, (referee) Bill Vinovich. You don't forget those things. How do you forget something like that?''