Arsenal were forced to substitute the young defender after 102 minutes of Tuesday's 4-1 Carling Cup victory over Tottenham Hotspur as Gibbs hobbled off the pitch.
Gibbs sustained a lengthy injury last season - depriving him of the chance to fight for a place in England's World Cup squad - and Wenger hopes a similar prognosis will be avoided.
"We have to check, that is the only disappointment of the night, because Gibbs had a very good game," Wenger said. "We hope we do not get bad news tomorrow morning [Wednesday].
"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."