Midfielder Gavin Williams says he will need two more injections as he tries to overcome his pelvic injury. The former West Ham and Yeovil man sustained the problem in the recent 0-0 draw at Stoke.
Williams said: "I have been told that I need another two injections and these need to be five days apart, so this takes me well into next week.
"Then it will be fingers crossed to see how quickly I can recover.
"I am at a stage when I have had enough of a stop-start season. So I don't plan to try to rush back and put myself in danger of breaking down.”
The Welsh international has again committed his future to Town, having previously revealed that manager Jim Magilton had made him available during the transfer window in the wake of the controversial Amsterdam trip.
Williams, who says his relationship with Magilton is fine, is contracted to the Blues until June 2009.
Central defender Richard Naylor is a doubt ahead of Saturday's trip to Watford due to his toe injury, while Jason De Vos is unlikely to be fit in time to face the Hornets having cracked a metatarsal in training last month. Alan Lee and Owen Garvan are both suspended for the trip to Vicarage Road and Jon Walters is cup-tied.