Unique player really is welcomed by crowd (7)
I believe the answer is:
soloist
'unique player' is the definition.
(musician with a unique part)
'really is welcomed by crowd' is the wordplay.
'really' becomes 'so' (both can mean 'extremely').
'welcomed by' is an insertion indicator (letters welcomed inside).
'crowd' becomes 'lot' (a lot of people).
'is' put within 'lot' is 'loist'.
'so'+'loist'='SOLOIST'
(Other definitions for soloist that I've seen before include "Individual musician" , "Individual performer" , "maybe a vocal type" , "musician at front of stage?" , "Main singer" .)