Spurs goal almost leads to defensive substitution (5)
I believe the answer is:
goads
'spurs' is the definition.
('goad' can be a synonym of 'spur')
'goal almost leads to defensive substitution' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'leads to' suggests taking the first letters.
The initial letters of 'defensive substitution' is 'ds'.
'goal' with its final letter taken away is 'goa'.
'goa'+'ds'='GOADS'
(Other definitions for goads that I've seen before include "Spurs" , "As dog (anag.)" .)