Enzo Maresca offered Raheem ­Sterling no assurances over his future after making the surprise decision to drop the winger when Chelsea began their season with a 2-0 defeat against Manchester City on Sunday, Erling Haaland and Mateo Kovacic scoring the goals.

Sterling, who has said through his representatives that he is looking for “clarity” over his status at Stamford Bridge, is one of several players who could be sold before the transfer window shuts this month. The 29‑year‑old, who has three years left on a deal worth more than £300,000 a week, was surprised not to have even a place on the bench for Maresca’s first competitive game in charge.

Related: Erling Haaland and Mateo Kovacic ease Manchester City to victory at Chelsea

“The only thing I can say was a technical decision and we will find clarity,” Chelsea’s new head coach said. “All the players, if they want to be Chelsea players we want to try and see how we can use them. I want Raheem Sterling but we have 30 players. Raheem, we will clarify in the next days.”

Chelsea are waiting to complete Conor Gallagher’s sale to Atlético Madrid, who are looking to send João Félix in the opposite direction. They hope to sign the Nigeria striker Victor Osimhen from Napoli, who want to buy Romelu Lukaku from the west London club. Maresca has said Ben Chilwell, the England left-back, is not in his plans and he also found no room for Trevoh Chalobah, Armando Broja and Carney Chukwuemeka in his match-day squad.

The Italian was asked if players seemingly destined for the exit can still impress him. “Carney is a very good player but I think the best thing for him is to play 30 to 35 games in a row and show how good he is,” he said. “For us, is he going to play 35 games? I don’t think so.”

Maresca defended his decision to hand the captaincy to Enzo Fernández a month after the Argentina midfielder was embroiled in a ­racism scandal. Fernández is still under investigation for a video in which he and other Argentina players sang an offensive chant about black France players. The incident went down badly with Chelsea’s French ­players, although the air has since been cleared.

“I did mistakes in the past and I ­recognise that,” Maresca said. “I think if as a human being you make a mistake and recognise you are not going to be punished for life.”

Pep Guardiola was delighted with City’s start to their title defence. Haaland opened the scoring before Kovacic sealed the points. “If you are the best team in England, 38 games we’re going to defend the crown, we have to behave like we were, a champion team,” Guardiola said. “Today I said we’d suffer moments, but it’s how we’ll help each other.”

City’s manager praised Haaland, who looked tired at the end of last season. “I had a feeling he feels better than last season at this stage,” ­Guardiola said. “His contribution in many things, there is a gap to improve as well.”

Haaland has scored 91 goals in 100 Premier League games. “Numbers like Messi and Cristiano Ronaldo, the last decade, 15 years, in terms of numbers,” said Guardiola, who was happy to win with Rodri missing through injury. “Rodri is massively important for us,” he added. “We are wishing him back as quickly as possible but for now it’s survive. Last season we couldn’t beat Chelsea, now we did it.”