The 26-year-old Brazil international will not travel to Portugal for Friday night's friendly against Benfica after undergoing tests on Wednesday.

Inter have not revealed the extent of the injury but reports in Italy suggest he could be out for around a month.

Adriano has only recently returned from a loan spell at Brazilian side Sao Paulo.

The striker fell out of favour with then then Inter boss Roberto Mancini last season was sent on loan to regain form and fitness.

Adriano was a revelation after moving back to Brazil, scoring twice on his debut in the Paulista tournament and going on to score six goals in the Copa Libertadores, but decided to return to Milan to try to win his place back under new boss Jose Mourinho.

Also out of Friday night's friendly are Cristian Chivu, Ivan Ramiro Cordoba, Julio Ricardo Cruz, Marco Materazzi and Walter Samuel.