Manchester City manager Pep Guardiola says Sergio Aguero will decide his own future, upon the expiry of his contract in June 2021.
Aguero has scored 244 goals in 355 appearances for City, including a famous Premier League-winning strike against QPR in 2012.
The 31-year-old is into the final 18 months of his contract and Guardiola admits it will be hard to replace him.
"I would say it will be one of the toughest things, he's irreplaceable," said Guardiola.
"We have an incredible striker in Gabriel [Jesus] and maybe will come another one when Sergio's leaving, but he's irreplaceable.
"I think the most important moment of this club, is the moment Sergio scored that goal against Queen's Park Rangers to win the first Premier League. That moment is much better than four titles in one season, and he was the guy.
"It's not easy to find a guy with his status, his personality, what he has done in the football career with this humility."
Guardiola is unsure of the Argentina international's plans regarding a new contract, but admitted it will be Aguero that makes the final call.
Asked whether he will sign a new deal, Guardiola replied: "I don't know. He can stay. It depends on his physical condition and his desire, but I didn't speak with him and I don't know his intentions.
"Sooner or later it's going to happen, he will decide when, and I'm sure the club will be ready to try to find the guy to try to replace Sergio, but of course it will not be easy.
"Sometimes I have to take a decision but in most of the cases it's the players who decide. These kind of players like Sergio decide if they want more or it's over."