The 32-year-old striker missed Saturday's 0-0 draw with Bolton with a calf injury sustained in training the previous day, leaving the manager with just 11 fit senior players.
Alan Smith and Nicky Butt will be available after suspension for Saturday's FA Cup fourth round trip to the Emirates Stadium, which will be followed four days later by a return in the league.
And there is an outside chance that Joey Barton, currently on bail after being charged with assault and affray, could figure this weekend with the conditions on his release from custody meaning has to be back at the Sporting Chance clinic in Hampshire by 7pm every night.