Ronaldo failed to get on the scoresheet in his winning debut at Chievo Verona.
But Szczesny says: “Cristiano Ronaldo is a great player and has already added a lot of quality to the team.
“Unfortunately he didn't score against Chievo, but he will score his first official goal very soon, I'm sure of it.
“For us to have a good year in the Champions League, we must first play well in the League. If we do that, it'll give us confidence."