Manchester City are waiting to discover the seriousness of Fabian Delph's hamstring injury after the England international was hurt on his debut.
Delph lasted less than 20 minutes in City's 4-1 defeat to Real Madrid in the International Champions Cup in Melbourne, and the former Aston Villa midfielder, who cost City £8 million, could be a doubt for the start of the Premier League campaign.
Manager Manuel Pellegrini said in a news conference: "Unfortunately, Delph has a problem with his hamstring. We will see tomorrow [Saturday] how bad it is. The plan was for him to play 45 minutes."
Pellegrini fielded the inexperienced duo of 16-year-old Cameron Humphreys and 20-year-old Jason Denayer at centre-back against the Real attack of Cristiano Ronaldo, Karim Benzema and Gareth Bale.
He said that his three central defenders were all unavailable, with Martin Demichelis yet to join up with City after playing a part in the Copa America, Vincent Kompany returning to England to attend the birth of his third child and Eliaquim Mangala falling ill.
Pellegrini added: "Mangala was sick this morning so he could not play and Kompany is becoming a father again so he is not here."
City were also without Sergio Aguero, Wilfried Bony, Pablo Zabaleta and Fernandinho, and Pellegrini said he was not worried by the defeat to the 2014 European champions.
"I'm not concerned as we have many missing players and then a lot of them have arrived late so they've worked just five days," he said.
The Roma target Edin Dzeko, who had been an unused substitute for City's two previous games, was brought on in the second half.
The Bosnian striker could move to Roma this summer, but Pellegrini said he was treating him in the same way as his other players.
He said: "He has just started working with the whole squad, he is a player of this squad and I don't make him any different."