By "access special methods" I assume you mean methods in just the OpenPlayer or just the ClosedPlayer?
By array, I assume you mean some STL collection ;-)
The short answer is "No".
The long answer is "Yes you can, but you'll need to cast objects to the correct type. This implies that your design is wrong."
A different disign might be to make "Open" or "Closed" a property of the Player class rather than individual subclasses.