The Australian is moving from the energy drink-owned team to Renault for 2019 and beyond.
“From Singapore, Daniel is excluded from any meetings that concern the future,” Red Bull’s Dr Helmut Marko told Bild newspaper.
“We are already working in the direction of 2019 and do not want him to take anything to Renault,” he explained.
However, Marko said there is no fear that Ricciardo could actually be ousted before the end of the season.
“Daniel will finish the season with us. He will get all the information in Singapore because it could be our last chance of winning this year,” he added.