PSV were beaten 2-1 in the first-leg in Turin with Samuel Mbangula striking late for the hosts.
Bosz said afterwards: "We suffered in the first five or six minutes, as Juventus pressed us very high, but after that we started playing football and controlling the game, even though Juve maybe had more the ball.
"But we controlled it and scored a fantastic goal in the second half. Unfortunately, they scored the second, but there is still another game to play."
PSV midfielder Jerdy Schouten also said, "My feeling is not good because we lost and we wanted to get the result. It didn't go well at the beginning of the game because they made us run too much. But everything is still open.
"Tonight we could have done more and been more dangerous. We need to do better in creating chances. We are not happy, but this result can still give us confidence.
"At home we are a very strong team, so we are confident ahead of the return match. We know that we can show all our energy. We leave Turin with the idea that everything is still open. We know that our real strength is at home."