Admire Rashford's header playing United (7)
I believe the answer is:
married
'united' is the definition.
(marrying is a kind of uniting)
'admire rashford's header playing' is the wordplay.
'header' says to take the initial letters (in a down clue, the letter at the top of the word).
'playing' is an anagram indicator.
The initial letter of 'rashford' is 'r'.
'admire'+'r'='admirer'
'admirer' with letters rearranged gives 'MARRIED'.
(Other definitions for married that I've seen before include "Closely linked" , "disqualified from new romance?" , "having a wife" , "Wedded" , "Admirer (anag)" .)