Manchester City manager Pep Guardiola says Sergio Aguero has to show he can still deliver on the pitch if he is to earn a new contract.
Aguero, who joined City in 2011 and is their all-time leading scorer with 254 goals, is out of contract at the end of the season and can speak to overseas clubs from January.
The 32-year-old sustained a knee injury in June and made his return in Saturday's 1-0 home win over Arsenal.
"Sergio now has to show, like every one of us, that he deserves to continue here - keep playing well, scoring goals and winning games - and after that the club and I will decide," Guardiola said.
"But if he's playing in his level we don't have any doubts that he's a player to stay until he decides because he's unique. He's important for us, our fans and everyone.
"But he was out four months and he has to start training regularly and start to score goals. Having Aguero on the pitch, we're better, safer. We missed him in the important moments at the end part of last season."
City, who are 10th in the Premier League with seven points from four matches, begin their Champions League campaign on Wednesday against Porto before a league meeting with West Ham United at the weekend.