Max Verstappen has said that he thinks he will have the same teammate in 2019.
At the moment, Daniel Ricciardo is linked with potential moves to Ferrari, Mercedes, McLaren or Renault, and he hopes his decision will be clear by the summer break.
Red Bull's Dr Helmut Marko is confident that the Australian will stay.
"We have recently come very close. It's on a good way," he told Kronen newspaper.
Dutchman Verstappen said that he would be happy if Ricciardo stays.
"The chances that he will stay are high," he said in Austria. "I see no reason why not.
"Daniel is a great teammate, we have a lot of fun together but on the track we motivate each other to push. I like working with him, he's one of my best teammates and also one of my most difficult rivals, but I like it."
Verstappen, 20, also said that he has put a recent spate of crashes behind him, and denied that it was the absence of his father Jos from the track that helped.
"He was never coming to those races anyway," the Red Bull driver insisted.
"He has his own life. I have a sister who is 3 years old and he wanted to spend time with his family. [Jos] will be here this weekend."
Red Bull go into Sunday's race 50 points adrift of second-placed Ferrari.