Toure credits manager Pep Guardiola for Sterling's improvement.
He said: “He is a top manager. Pep is the type of guy who can take a talent and get it to its maximum level.
“Raheem, my little brother, joined when (Manuel) Pellegrini was at the club. Since Pep arrived Raheem is in another world. He is complete.
“Pep has given him the confidence he has needed. When he played for Liverpool I was always scared of him because he is short and so fast, so quick! Him and Suarez and Coutinho? They were unplayable.
“But when he first arrived at City I had to ask myself when it was the right choice for him because he was struggling a lot.
“He had a lot of criticism and it was hard for him. But he continued to work and now he deserves the Player of the Year."