Manchester - Manchester City captain Vincent Kompany sustained a calf injury during his side's 2-1 Champions League defeat at home to Juventus on Tuesday.
"Vincent has a calf injury," City manager Manuel Pellegrini told his post-match press conference.
"We will see tomorrow (Wednesday) how important it is."
Kompany pressured Giorgio Chiellini into scoring an own goal that put City ahead in the 57th minute at the Etihad Stadium, but was forced off in the 75th minute after Mario Mandzukic had netted an equaliser.
Nicolas Otamendi replaced Kompany to make his City debut, but six minutes later Alvaro Morata netted the winner for Juventus in the Group D opener.