Leroy Sané could be ruled out until March by the knee injury he suffered in Manchester City’s Community Shield win over Liverpool. Tests have revealed anterior cruciate ligament damage and the 23-year-old forward will have surgery at the clinic of Ramon Cugat in Barcelona next week.

Pep Guardiola said: “Normally this kind of injury is six or seven months – hopefully in February or March he can be back. It’s bad news as in three seasons we’ve had three ACLs [Benjamin Mendy and Ilkay Gündogan were the others].

He’s young and he will recover well hopefully in terms of the surgery. All the people will help him. He will feel alone and we help him to feel as comfortable as possible.”

Sané was targeted by Bayern Munich in the summer transfer window but Guardiola said: “I didn’t think about him leaving. I always said he’s our player and he didn’t tell me he wanted to leave. Always I thought he was ours.”

Guardiola is confident City have adequate cover. “The fact he’s not here – in the first season we didn’t have Gündogan, then Benjamin [and we still managed],” the manager said.

Following Vincent Kompany’s departure David Silva was elected captain by his teammates. “David Silva will be our captain with Fernandinaho, Kevin [De Bruyne] and Sergio [Agüero] as deputies,” Guardiola said. “David has to be what he is. He’s one decade here, knows the Premier League and has big respect.”

City, who are aiming to join Manchester United as the only team to win three consecutive titles in the Premier League era, start their season at West Ham in Saturday’s early game. Guardiola believes he has no reason to question his players after their historic domestic treble.

“In the beginning [of pre-season] we spoke about mentality, and why should I doubt them after what they’ve done?” he said. “In China [on tour] they did it and this week especially, in training they are so focused, [although] that isn’t a guarantee to win games. But without that it’s impossible; that’s the first step. When I see that I can see we will be competitors.

“Last season when you asked me about back-to-back titles I said it’s tough. Of course it would be great and incredible [to win a third] but when you are in this position, you try to make the team play good, don’t think too much – there is no sense to think about the Premier League as it’s far away. We should prepare for each of the first four games.”

Riyad Mahrez has been cleared by UK Anti-Doping after fears he could fail a doping test ruled him out of selection for the Community Shield. He had taken an unknown medicine while on international duty. “After this week they came and tested him and he’s ready for tomorrow,” Guardiola said.