More to come in the next race (5)
I believe the answer is:
extra
'more' is the definition.
(I've seen this in another clue)
'come in the next race' is the wordplay.
'come in' says the answer is hidden in the clue (I've seen 'coming in' mean this).
'EXTRA' is hidden in the letters of 'next race'.
'to' acts as a link.
(Other definitions for extra that I've seen before include "spotted at rear of the platoon?" , "A bit on the side" , "comes to 16 [TEST MATCH]" , "Cricket run; unusually" , "Not a standard item" .)