It is another blow for Iwelumo after he had missed the climax to Wolves' promotion campaign with knee ligament damage.
Wolves boss Mick McCarthy, whose side face Arsenal on Saturday, said: "Chris is not fit.
"He has damaged the fracture site. He has not refractured the metatarsal so please don't go away and say 'It is broken' because he hasn't done that.
"He has unsettled it more than anything and he will be a few weeks out. It doesn't happen normally but Sorensen and Berra fell on him when he got his foot planted (in the ground).
"Where the actual fracture is and the metal screw goes in, it has been unsettled, disturbed, but not broken."
McCarthy added: "It is a big blow after all he has gone through. He played well last week at Stoke and to have him back was a real bonus.
"It is sad for him, the Stoke game was his first back in the Premier League and the Stoke game suited him, the physical nature of the game."
McCarthy confirmed that striker Sylvan Ebanks-Blake would return against the Gunners, whether or not Iwelumo had been fit.
Ebanks-Blake scored his first Premier League goal from the penalty spot in the 1-1 draw with Aston Villa a fortnight ago, but was replaced by Iwelumo at the Britannia Stadium.
McCarthy said: "Sylvan was always playing against Arsenal, whether Chris was injured or not. He was left out purely tactically at Stoke."