Not the plan being injured for athletic event (10)
I believe the answer is:
pentathlon
'athletic event' is the definition.
(I've seen this before)
'not the plan being injured' is the wordplay.
'being injured' is an anagram indicator.
'not'+'the'+'plan'='nottheplan'
'nottheplan' with letters rearranged gives 'PENTATHLON'.
'for' acts as a link.
(Other definitions for pentathlon that I've seen before include "old Olympic event" , "sports event" , "athletic contest" , "Sporting event with five disciplines" , "Fivefold athletic event" .)