Napoli striker Lukaku might require thigh surgery ahead of season

Napoli striker Romelu Lukaku may require surgery after sustaining a left thigh injury during a preseason friendly, the Italian champions said Monday.

The Belgium international was substituted in the 2-1 win over Olympiacos on Thursday.

Tests showed Lukaku has a high-grade damage to the thigh muscle in his left leg, said Napoli, which added that the striker has already begun his rehabilitation program and will also undergo a surgical consultation. 

Napoli, which didn't give a potential timeframe for Lukaku's absence, begins the defense of its Serie A title against Sassuolo on Saturday.

Belgium will also be keen to know the seriousness of the injury to its all-time record scorer, with World Cup qualifiers scheduled for the team in September, October and November.