From some games I watched merkel,I'm not convinced that he will be great some day. his skill set is not very advanced,he is not gattussoique body-type,he doesn't have 3 lungs like nocerino.what impress me is his mental and technical maturity.I would only say he can be very solid,his potential lies with how he can improve his skill.a natural similar player comes to my mind is albertini.
May god with chinese footbball