One in the forefront of football? (3)

I believe the answer is:

ref

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'football?' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.

'one in the forefront of' is the wordplay.
'one in' indicates the answer is hidden within the clue.
'REF' is hidden within 'forefront of'.

Can you help me to learn more?

(Other definitions for ref that I've seen before include "Sports official (abbrev.)" , "Sports umpire" , "Football official (colloq.)" , "Football's whistler" , "Middleman needing cards" .)

I've seen this clue in the Evening Standard.

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