Lambert, who injured his foot in an old firm encounter a couple of weeks ago, is struggling to make it for Saturday and today's news will not be welcomed by Celtic boss Martin O'Neill.
Meanwhile, over at Hampden, O'Neill was left standing twiddling his thumbs as Rangers boss Alex McLeish failed to arrive in time for a joint press conference.
Eventually, an angry O'Neill got fed up waiting, said his thoughts to the assembled press and then departed just as McLeish arrived.
This snub will not go down to well with O'Neill who is bound to see it as an insult. McLeiah would not comment on the matter during his press conference.