Enthusiastic soccer official recalled opening (7)
I believe the answer is:
fervent
'enthusiastic' is the definition.
(fervent can mean passionate or earnest)
'soccer official recalled opening' is the wordplay.
'soccer official' becomes 'ref' (short for referee).
'recalled' says the letters should be written backwards.
'opening' becomes 'vent' (vent is a kind of opening).
'ref' back-to-front is 'fer'.
'fer'+'vent'='FERVENT'
(Other definitions for fervent that I've seen before include "Intensely passionate" , "Impassioned" , "Zealous" , "Ardent" , "Hot" .)