Champ suffering with loss of a wicket (4)
I believe the answer is:
chew
'champ' is the definition.
(I know that champ is a more specific form of the action chew)
'suffering with loss of a wicket' is the wordplay.
'suffering' becomes 'ache' (I've seen this before).
'with loss of' suggests deleting specific letters.
'wicket' becomes 'w'.
'ache' with 'a' taken away is 'che'.
'che'+'w'='CHEW'
(Other definitions for chew that I've seen before include "Work or grind between teeth" , "Masticate, grind between teeth" , "Bite repeatedly" , "Reflect on" , "Process food" .)