The Bosnia international has already undergone surgery following the clash of heads during their 1-1 draw with Cagliari last Sunday.
“It was a bad fracture, worse than previously thought," Professor Bruno Pesucci told the Corriere dello Sport after performing the operation to stabilise it.
“Initially, we believed it was just the cheekbone that had been fractured, but then we found another fracture towards the lower part of the orbital bone around the right eye.
“It was necessary to perform an ostoeosynthesis procedure, with the use of a plaque held in place by screws to stabilise the orbit. It was the only way to contain the fracture.
“In other cases, I'd dealt with isolated fractures, but Edin's injury was more complicated, because it's a double fracture and so will take longer to heal.
“A carbon mask might not be sufficient to protect an injury like this. In order to consolidate the bones, we need three or four weeks.
“It's best to be cautious in these situations, as a rush could be damaging."