It is very popular that Football teams are known by nicknames; this is why Valencia C.F. are also called the ‘che club’.
Some people could think that this tradition comes from Argentina or Uruguay –they use the Word ‘che’ very often-, but in Valencia they have also been using it since centuries. In Valencian/Catalan, ‘Che’ or ‘xe’ is a colloquial slang used in a vocative sense as “friend”.
Valencia C.F. are known as ‘che’ because this is the best word to define the team and everything related to the club. Che team, che fans, che stadium… Che means Valencia!
Now you know the point: ‘che’ is not only Argentinian or Uruguayan, but also Valencian!