Barão and Wineland were supposed to headline the upcoming UFC 161 fight card on June 15 at MTS Centre in Winnipeg, Manitoba, Canada.
Barão (30-1) won the interim belt with a five-round unanimous decision victory over former WEC champion Urijah Faber at UFC 149 in Calgary last summer.
The Brazilian champion had hoped to wait for UFC bantamweight champion Dominick Cruz to return from injury before fighting again. When Cruz’s recovery was delayed, Barão defended his belt against Michael McDonald at UFC on Fuel TV 7 in London in February. He submitted McDonald late in the fourth round.
The fight with Wineland was to be Barão’s second interim title defense.
The UFC has not yet announced how it will handle the UFC 161 fight card with Barão on the sidelines.