American change of direction requires nerve after a fight (5,4)
I believe the answer is:
about face
'american change of direction' is the definition.
'nerve after a fight' is the wordplay.
'nerve' becomes 'face' (synonyms).
'after' says to put letters next to each other.
'fight' becomes 'bout' (as in a bout in boxing).
'a'+'bout'='about'
'face' put after 'about' is 'ABOUT-FACE'.
'requires' acts as a link.
(Other definitions for about face that I've seen before include "turnaround" , "180 degree turn" , "Reversal" , "U-turn" , "retreat" .)