Man with cue, getting break, displays keen perception (6)

I believe the answer is:
acumen
'keen perception' is the definition.
(I've seen this before)
'man with cue getting break' is the wordplay.
I cannot quite understand how this works, but
'man' could be 'n' (knight, a man in chess) and 'n' is located in the answer.
'with' could be 'cum' ('with' in Latin) and 'cum' is located in the answer.
The remaining letters 'ae' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'displays' is the link.
Can you help me to learn more?
(Other definitions for acumen that I've seen before include "Mental sharpness as in business" , "Forming judgement" , "Shrewdness, intelligence in business" , "Good judgment" , "'Shrewdness, in business perhaps (6)'" .)