The German midfielder picked up a slight knock on his left knee, not the one that was operated on back in January, after playing his first full game for the reserves last week.
The boss revealed: "Steffen unfortunately has just picked up another slight knock just behind the other knee.
"That's knocked him a little. Nothing big, but he isn't ready yet anyway.
"He needs four to five reserve games under his belt first and to make sure that knee is 100 per cent right. When he comes back, it has to be 100 per cent.
"He hasn't trained since the reserve game but these things can happen when you first come back."
Glenn Hoddle reports that Steffen Freund has suffered a slight setback in his return from long-term injury.