Five hundred in unusual Spanish football gear (4,4)
I believe the answer is:
shin pads
'football gear' is the definition.
(part of a football kit)
'five hundred in unusual spanish' is the wordplay.
'five hundred' becomes 'd' (Roman numeral for 500).
'in' means one lot of letters goes inside another.
'unusual' is an anagram indicator.
'spanish' with letters rearranged gives 'shinpas'.
'd' inserted into 'shinpas' is 'SHIN PADS'.
(Other definitions for shin pads that I've seen before include "Protection for the lower legs" , "Batsman's protectors" .)