Marginal footballer in debt with no capital (4)
I believe the answer is:
wing
'marginal footballer' is the definition.
(footballer positioned on one side of the pitch)
'in debt with no capital' is the wordplay.
'in debt' becomes 'owing' (I've seen this before).
'with no capital' means to remove the first letter.
'owing' with its initial letter removed is 'WING'.
(Other definitions for wing that I've seen before include "Part of a building; fly" , "Chicken portion" , "Pinion" , "Footballer" , "Organ of flight" .)