The German is wary of Belgium's players being able to communicate in French with Djamel Haimoudi and his team of officials.
USA also beat Haimoudi's homeland in a last-gasp group-stage match at the last World Cup - helping USA through to the knockout rounds - which Klinsmann also cited among his fears.
The States impressively qualified through a tricky Group G this time around, over Portugal and Ghana, and Klinsmann is keen for his side's ability on the pitch to be the only factor in their continued presence in Brazil.
"We hope it's not a concern," Klinsmann said.
"We know that already he did two games very well so we hope he continues that tomorrow.
"Is it a good theory? No. He is able to speak French with their players on the field and not with us.
"And it's a country that we beat in the last second in the last World Cup.
"I understand it's difficult for FIFA to choose the right referees for the right games and it has always been tricky for FIFA, but it is what it is.
"We give it the benefit of the doubt, we respect the decision and hope that everything goes well."
