The 19-year old striker is on a season-long loan from Tottenham but has managed just two appearances after sustaining the foot problem in the Capital One Cup win over Doncaster Rovers in September.
"Harry has completed about five days training in total, four of them with Tottenham. He is at the stage now where he has to keep developing his fitness," said the Norwich boss.
"We have to determine over this next week or so when he is available for games. I think he has done a lot of good rehab, which is good news for us.
"I feel for the lad because he came here with a real spring in his step.
"The good thing is he is young and the type of injury he had, he will make a full recovery from, possibly for Christmas, but it is too soon to assess yet. He needs a week's training."