Rugby player happy to provide support (4,2)
I believe the answer is:
back up
'provide support' is the definition.
(I've seen this before)
'rugby player happy' is the wordplay.
'rugby player' becomes 'back'.
'happy' becomes 'up' (I've seen this in other clues).
'back'+'up'='BACK-UP'
'to' acts as a link.
(Other definitions for back up that I've seen before include "Support - reverse" , "Copy of a file on a separate storage device" , "Support, assist" , "Give support" , "provide support" .)