Manchester City prepare to face West Ham knowing they could miss Fernandinho for as long as six weeks after the midfielder limped off against Porto.
The Brazilian came on as a substitute in the Champions League win, but lasted all of nine minutes.
It worsens the defensive headache for Pep Guardiola, who also saw Nathan Ake withdraw from the game with a groin injury. The summer signing should be fit for Saturday.
Kevin De Bruyne and Aymeric Laporte are nearing a return to fitness and could make the bench at the London Stadium, though Guardiola was coy when asked for an update on Friday.
He said: "Yes, some of them will be involved, some of them no. You will know tomorrow."
Further forward, Gabriel Jesus and Benjamin Mendy remain sidelined which means Sergio Aguero should lead the line again, with Riyad Mahrez and Raheem Sterling either side.
Predicted Manchester City XI to face West Ham (4-3-3): Ederson; Walker, Dias, Ake, Zinchenko; Gundogan, Rodri, Foden; Mahrez, Aguero, Sterling
