Papers showing what striker wants from full-back -- Rio, for instance (8)
I believe the answer is:
passport
'papers' is the definition.
(passport is a kind of papers)
'what striker wants from full-back rio for instance' is the wordplay.
'what striker wants from full-back' becomes 'pass' (passing the ball).
'rio for instance' becomes 'port' (Rio de Janeiro is a port).
'pass'+'port'='PASSPORT'
'showing' is the link.
(Other definitions for passport that I've seen before include "Document facilitating travel" , "entry permit?" , "is the open sesame" , "Carte blanche" , "This ensures admission" .)