The Liverpudlian goes up against the heavy-hitting Stevenson in Canada, and Conteh wants his fellow Scouser to make sure the result is taken out of the judges' hands on the night.
"He is away from home and so needs to try and win every round, that may mean he has to take risks," Conteh told the Liverpool Echo.
"Tony certainly does not want to be fighting out of his control. He needs to be in charge of this fight. He needs to leave everything in the ring and believe in himself.
"Stevenson can punch. He is a great champion and Tony knows exactly what he is facing, but Bellew has good boxing skills and can punch hard himself. He is good enough to do it."
Bellew was victorious in his last fight against Isaac Chilemba in May.