BortolamiÂ suffered an injury to his left eyeÂ during last weekend's 29-21 victory over MunsterÂ in the Heineken Cup and further tests carried out in Rome confirmed the Gloucester captain has fractured two bones in his orbital zone.
"Bortolami isÂ on his way to Milan to have further check-ups toÂ evaluate if he needsÂ to undergo surgery," Andrea Cimbrico, Italy Rugby Federation'sÂ press officer said.
"Due to the delicate position of the fractures, it is expected that he will be out of action between four to six weeks."
Italy coach Nick Mallett will have to do without the experienced Bortolami for the RBS 6 Nations opener against Ireland in Dublin on February 2 as well as the home game against England eight days later.
The former Italy captainÂ could return in time to face Wales at the Millennium Stadium on February 23.