Aymeric Laporte has been ruled out until September as he continues his recovery from knee surgery.
It means Pep Guardiola only has five fit senior defenders for the start of the season after Oleksandr Zinchenko was sold to Arsenal with Ruben Dias, John Stones and Nathan Ake the three main options at centre-back.
Guardiola praised Laporte for playing through the pain barrier at the end of last season, when Dias, Stones and Kyle Walker all had injuries, and postponing his own operation.
“Laporte is injured,” said the City manager. “He had knee surgery after last season and played the last two or three games with an important injury. He made an incredible effort. He had surgery. So far he is doing really well but you have to be careful with a knee. I think August he will be out. I think maybe he will start to be with us in September.”
Guardiola confirmed he wants to sign a new left-back, adding “If it is possible, yes. If not, we stay with what we have.”
City have bid for Marc Cucurella, who has submitted a transfer request in a bid to leave Brighton. Guardiola added: “He is a Brighton player, I cannot say anything else.”