Highlights achievement by United, regarding soccer header (8)
I believe the answer is:
features
'highlights' is the definition.
(I've seen this before)
'achievement by united regarding soccer header' is the wordplay.
'achievement' becomes 'feat' (feat is a kind of achievement).
'by' means one lot of letters go next to another.
'united' becomes 'u' (as in Man U, English football team).
'regarding' becomes 're' ('re' means regarding or about).
'header' suggests taking the first letters (in a down clue, the letter at the top of the word).
The initial letter of 'soccer' is 's'.
'feat'+'u'+'re'+'s'='FEATURES'
(Other definitions for features that I've seen before include "Highlights" , "Facial characteristics or newspaper articles" , "Plays an important role" , "Parts of the face, e.g., eyes, nose, mouth" , "Characteristic parts of a person's face" .)