The Reds return to Europe's top club competition after a five-year absence when they host Ludogrets Razgrad at Anfield on Tuesday, and Coutinho is expecting great things from his 19-year-old teammate.
The Brazilian was quoted by The Mirror as saying: "It is likely that Raheem Sterling will be one of the stars in Europe for Liverpool.
"Raheem is having a very good time at the moment and is in very good shape, so I believe he will do well this season.
"Like me, Raheem wants to attack defenders, but the difference between us is that he is very, very fast. I ¬definitely don't have the speed to catch Raheem."
Sterling came on as a substitute in Liverpool's 1-0 defeat at home to Aston Villa on Saturday.