Spoken/headline shorthand only. The full club name in Chinese is 巴塞罗那足球俱乐部. Use 巴萨 in casual conversation or fan contexts; formal articles still spell out the full name first.
巴萨 is the Chinese shorthand for the Catalan football giant — pulled from the first syllables of 巴塞罗那. Their rivalry with Real Madrid (皇马) is called 国家德比 (El Clásico) in Chinese sports media.