Pit workers abandoned short race? (9)
I believe the answer is:
orchestra
'pit workers' is the definition.
(people working in the orchestra pit in a theatre)
'abandoned short race?' is the wordplay.
'abandoned' indicates an anagram (the original order is abandoned).
'short'+'race'='shortrace'
'shortrace' is an anagram of 'ORCHESTRA'.
(Other definitions for orchestra that I've seen before include "Theatre area for musicians" , "players in pit" , "Gamelan, for instance" , "Large band of musicians" , "Group of musicians found on cart-horse" .)