Competitor expected to lose (8)
I believe the answer is:
underdog
'competitor expected to lose' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for underdog that I've seen before include "Grounded (anag)" , "Someone at a disadvantage and likely to lose" , "One at a disadvantage" , "Unfancied performer" , "Likely loser" .)