Manchester City striker Roque Santa Cruz has been ruled out for at least a month by a recurrence of a calf injury sustained in the 2-0 weekend defeat at Everton.
The 28-year-old Paraguay international lasted just nine minutes of the Goodison Park reverse, having been sidelined for several weeks either side of Christmas due to the initial injury.
Manager Roberto Mancini told the club's official website: "It looks like a bad injury for Roque, it is to the same calf that was a problem around Christmas.
"It could be around one month, we don't know exactly when he'll be back yet. It does not require surgery, just treatment."
Meanwhile, recent signing Patrick Vieira's debut for the Citizens will be delayed by a calf injury, with the veteran midfielder ruled out for at least another week.
Mancini added: "It's better for us and for him if he can be ready to play in another week or ten days.
"It's better that we don't risk his situation because I would like that when Patrick comes back, he can play to the end of the season.
"I would want him to be ready to play 20 games."