Half of Spanish football team leaving the field (5)
I believe the answer is:
realm
'the field' is the definition.
('realm' can be a synonym of 'field')
'half of spanish football team' is the wordplay.
'half of' means to take half the letters.
'spanish football team' becomes 'realmadrid' (I've seen this before).
'realmadrid' halved is 'REALM'.
'leaving' is the link.
(Other definitions for realm that I've seen before include "Empire - state" , "Kingdom's" , "Royal domain" , "the UK, perhaps" , "field of study" .)