The 20-year old limped off during extra-time of Arsenal's 4-1 Carling Cup third round win over Tottenham on Tuesday night with what seems to be a recurring metatarsal problem in his foot.
Wenger was keeping his fingers crossed after the match, hoping that the trouble was not too serious.
"We have to check, that is the only disappointment of the night, because Gibbs had a very good game," said the Gunners manager.
"We hope we do not get bad news tomorrow morning.
"It is a metatarsal again, it is the one next to the one he had broken, the second one, so we hope we have good news tomorrow morning, because that would be a massive blow to us."