Crossbar split goalie's head (4)
I believe the answer is:
rung
'crossbar' is the definition.
(I've seen this in another clue)
'split goalie's head' is the wordplay.
'split' becomes 'run' (split can mean to run away).
'head' indicates taking the first letters.
The initial letter of 'goalies' is 'g'.
'run'+'g'='RUNG'
(Other definitions for rung that I've seen before include "Telephoned" , "Tolled - step on ladder" , "Crosspiece of a ladder" , "Step up the ladder - called for" , "Level in a hierarchy" .)