Idiot seconds from time essentially steers ball to goalscorer (6)
I believe the answer is:
assist
'time essentially steers ball to goalscorer' is the definition.
I can't judge whether this definition defines the answer.
'idiot seconds' is the wordplay.
'idiot' becomes 'ass' (both can mean a stupid person).
'seconds' becomes 'ist' (I can't explain this - if you can you should believe this answer much more).
'ass'+'ist'='ASSIST'
'from' acts as a link.
Can you help me to learn more?
(Other definitions for assist that I've seen before include "Work as a subordinate" , "Provide aid, help out" , "Be useful to" , "providing help?" , "Understand by instinct" .)