Regular on the Spanish team? (6)
I believe the answer is:
eleven
'team' is the definition.
(eleven is a kind of team)
'regular on the spanish' is the wordplay.
'regular' becomes 'even' ('even' can be similar in meaning to 'regular').
'on' says to put letters next to each other.
'the spanish' becomes 'el'.
'even' after 'el' is 'ELEVEN'.
(Other definitions for eleven that I've seen before include "Number, on a team maybe" , "XI as Roman numeral" , "sports team?" , "Football side" , "Number on a side (6)" .)