Grey, wet second half of season upset winger from overseas (5,5)

'winger from overseas' is the definition.

'grey wet second half of season upset' is the wordplay.
I cannot really understand how this works, but
an anagram of 'grey' is 'yegr' which is within the answer.
'second' could be 's' (common abbreviation) and 's' is located in the answer.
'of' could be 'o' and 'o' is located in the answer.
This may be the basis of clue (or it may be nonsense).