Ends rough; my steer injured poet (9)
I believe the answer is:
rhymester
'poet' is the definition.
(I know that rhymester is a type of poet)
'ends rough my steer injured' is the wordplay.
'ends' says to hollow out the word (remove centre letters).
'injured' is an anagram indicator.
'rough' with its middle removed is 'rh'.
'my'+'steer'='mysteer'
'mysteer' with letters rearranged gives 'ymester'.
'rh'+'ymester'='RHYMESTER'
(Other definitions for rhymester that I've seen before include "Writer of short poems" , "Would-be poet" , "Poor poet" , "mediocre poet" , "Versifier" .)