Pep Guardiola says everyone has to show they "deserve to continue" at Manchester City, including Sergio Aguero with the striker's contract running out at the end of the season.
The Argentine made his first appearance in four months, after recovering from a knee injury, as City beat Arsenal 1-0 on Saturday.
City have said they remain relaxed about Aguero's contract situation and that of Guardiola, whose own deal is also set to finish at the end of the season.
The City boss says he has no doubts about the 32-year-old's quality but says that everyone at the club needs to earn a new deal.
“The important thing is that Sergio comes back in good physical condition, starts to get his rhythm, doesn’t get more injuries and and plays good,” he said.
"We know what he means for us, we know how we appreciate him, but now he has to show like everyone of us, me first, that we deserve to continue here and playing good and winning games.
“After that, the club and myself of course decide, but when he is playing in his level and we don't have any doubts he is a player to stay until he decides [to go] because he is unique, the numbers, he is important for us, the fans and for everyone.
“Having Sergio on the pitch, we are better, we are safer. We missed him a lot in important moments in the later part of the season. Now it is good news for us today that he is back."
Aguero has been with City since 2011 and has become the club's greatest ever goalscorer, as well as the highest-scoring non-Englishman in the Premier League and the fourth-highest goalscorer in the competition's history.
Italian giants Inter have been linked with a free transfer move for him next summer but there are sure to be other clubs interested in him if he becomes a free agent.
Meanwhile, Aguero will not face any retrospective punishment after he was criticised for touching assistant referee Sian Massey-Ellis during the victory over Arsenal.
He found himself at the centre of controversy just before half-time at the Etihad Stadium after he took exception to a throw-in decision.
The striker confronted Massey-Ellis and put his hand on her by the shoulder near her neck, before his arm brushed across her back. Massey-Ellis reacted by swatting Aguero's arm away.
City are already without fellow striker Gabriel Jesus with a thigh injury and Guardiola is not putting a timescale on his possible return.
But he warned that the club are taking a cautious approach to the Brazilian's setback.
"The injury he has is in the quadricep in the front of his leg and I think we will have to be calm and cautious," he said. "He is still not on the field training."
