Concentrated but looking embarrassed, cued poorly (7)
I believe the answer is:
reduced
'concentrated' is the definition.
('reduce' can be a synonym of 'concentrate')
'looking embarrassed cued poorly' is the wordplay.
'looking embarrassed' becomes 'red' (I've seen this before).
'poorly' indicates anagramming the letters.
'cued' is an anagram of 'uced'.
'red'+'uced'='REDUCED'
'but' acts as a link.
(Other definitions for reduced that I've seen before include "Abridged" , "Diminished - cut-price" , "Made less in size etc" , "Impoverished" , "Shortened" .)