Jim Gavin's departure is "very much a setback" for Dublin, according to Ciaran Whelan.
The five-in-a-row-winning manager called time on his seven-year tenure in a statement released by Dublin GAA this afternoon.
Speaking to RTÉ Sport, former Dublin midfielder Whelan said: "It did come as a surprise but I kind of felt that after the All-Ireland victory that he gave more back to the media, he walked around Croke Park.
"I got that sense all year that he was going to create a bit of history and maybe he’d move on because of his family and job commitments and the huge demands that are involved in the job.
"He owes absolutely nothing to Dublin football, what he has achieved is just incredible, over his tenure to lose just one championship match.
"It’s a massive loss really because that expectation had build over the last few weeks that he was staying on, that he was planning for next year. There was no hint that he was going to go at this point.
"He took the baton off Pat Gilroy, when there was a team there that finally believed in themselves.
"He created a culture of leadership from within the group and went on to deliver a phenomenal amount of success so [this is] very much a set-back this morning."
Also speaking to RTÉ Radio 1's former Kerry defender Tomás Ó Sé added that replacing Gavin will not be easy.
"It is going to be a tough job for Dublin to replace him," he said.
"They are still a very successful team, the show goes on.
"Dessie Farrell is a name [that might be in the mix] because Gavin came in from the U21s.
"Everybody will say, 'ah he had the players' and everybody talks about the culture of Dublin and how they are empowered as players to produce what they did on the field – it was Gavin who did all that.
"Gilroy got them over the line but it was Gavin who drove that team for the last five years.
"When I heard [the news] first of all, and it's a selfish Kerry thing, [I thought] if he goes will [some] players go as well?
"Because of they do then it’s great for the rest of us.
"I would say that there would be players in the Dublin squad that would be thinking, ‘there’s a thing going on here for the last four or five years, we know how it works, who’s in charge of what, what our place is within the squad'.
"That dynamic is going to be changed now."