The Bianconeri did reach the last four of the Europa League but could not beat Benfica to set up a meeting with Sevilla in the final that will be played at the Juventus stadium.
Conte is unsure that he can bring success in Europe to the club with the current squad he has.
"We need to understand if we have room for improvement and in this respect, I have my doubts," he said. "I believe Juventus are worth to be at least in the top eight in the Champions League and top four in the Europa League.
"But I cannot sell false hope to the fans, as I am a realist and need to point out that it’s very difficult to do better than that."
Conte won the Champions League as a player with Juve in 1996 and would like nothing more than to lift again the trophy, this time as a manager.
"I won it as a player and one day I want to win it as a coach," he said. "But if you ask me if it’s possible to do this with Juventus, I would say no."
Juve end the campaign at home to Cagliari on Sunday.