Invoke() method from another class?

Question

C++ / C#

I want to call Invoke() on a method from another class, like this:

public void ApplyBuff(Buff buff)
{
        Invoke("ball.IncBallSize", 10.0f);
}

Throws an error: "Trying to Invoke method: LevelBuffManager.ball.IncBallSize couldn't be called."
How to fix it and what needs to be done for this?