Twenty-five-year-old Kitson, who was voted the club's Player of the Year for 2004, has not played since before Christmas and is unlikely to make a first team comeback soon.
In his absence the toothless Royals have managed to fire a measly four goals in 2005, two of which have come against lower league opposition.
Steve Coppell had been hoping that Kitson would be ready to make a first team comeback by the end of January, but physio Jon Fearn revealed that the ginger-haired striker faces at least another month on the sidelines.
"In an ideal world he'll be back in three or four weeks but that really is the best possible scenario. We all want him back as soon as possible but we have to do what's best for him," said Fearn, speaking to the official site.
"I really don't know how long it will be before he's back, like with any injury he can still suffer a setback at any time so we won't know until we get there.
"We'll take each day as it comes but he's already doing things he couldn't do before, that's a good sign and we'll take it progressively."
Ageing forward Nicky Forster has struggled for form in recent weeks whilst over-the-hill marksman Les Ferdinand has struggled for match fitness and played just twice since his arrival at the club shortly after the New Year.
The Royals are yet to win in the league in 2005 and have been relying on Forster and Ingimarsson to score their goals.