Opposed to getting soft with a rival (9)
I believe the answer is:
contender
'a rival' is the definition.
('contender' can be a synonym of 'rival')
'opposed to getting soft' is the wordplay.
'opposed' becomes 'con' (I've seen this before).
'to getting' says to put letters next to each other.
'soft' becomes 'tender' ('tender' can be similar in meaning to 'soft'**).
'con'+'tender'='CONTENDER'
'with' acts as a link.
(Other definitions for contender that I've seen before include "One striving" , "One fighting others (for something)" , "Struggler in rivalry" , "One who strives" , "One struggling" .)