Blossoming after score in rugby test (3,3)
I believe the answer is:
try out
'test' is the definition.
(try out can mean to test or trial)
'blossoming after score in rugby' is the wordplay.
'blossoming' becomes 'out' (I've seen this in other clues).
'after' means one lot of letters go next to another.
'score in rugby' becomes 'try'.
'out' put after 'try' is 'TRY-OUT'.
(Other definitions for try out that I've seen before include "Sample" , "Put to experimental use" , "Test and evaluate" , "Taste" .)