He's around at the preliminary races (5)
I believe the answer is:
heats
'preliminary races' is the definition.
(I've seen this in another clue)
'he's around at' is the wordplay.
'around' is an insertion indicator.
'hes' enclosing 'at' is 'HEATS'.
'the' is the link.
(Other definitions for heats that I've seen before include "Eliminating rounds in a contest" , "Haste (anag.)" , "Eliminating rounds of a race" , "Warms up for the preliminary races" , "Makes hot or warm" .)