The £6m signing arrived at St Andrews from Valencia last summer but found it difficult to adapt to English football during his early time at the club.
Recently though the Serbia international is showing signs of quality and has netted three goals in his last four games for the Blues.
"A player like Crouchy is someone he can learn from," he said in the Daily Star.
"He's had to change his game. To get what we want from him means he's having to adjust to a style that he's maybe never experienced.
"He's just had to find his feet. He's an international player with a lot of experience playing in Europe so he's no mug."