Goal? Fail to score with keeper getting back (7)
I believe the answer is:
mission
'goal?' is the definition.
'fail to score with keeper getting back' is the wordplay.
'fail to score' becomes 'miss'.
'with' says to put letters next to each other.
'keeper' becomes 'noi' (resembles No 1, term for a goalkeeper in football).
'getting back' says the letters should be written backwards.
'noi' backwards is 'ion'.
'miss'+'ion'='MISSION'
(Other definitions for mission that I've seen before include "Task assigned to be done" , "In religious campaign" , "religious establishment" , "1996 Tom Cruise spy film -- extremely dangerous assignment" , "Ministry sent by a church to spread its teaching" .)