Approaches Arsenal about wanting a midfielder (5)
I believe the answer is:
nears
'approaches arsenal' is the definition.
'nears' can be an answer for 'approaches' ('near' can be a synonym of 'approach'). I'm not sure about the 'arsenal' bit.
'about wanting a midfielder' is the wordplay.
'about' becomes 'near' (synonyms).
'wanting' means one lot of letters go next to another.
'a midfielder' becomes 's' (I can't explain this - if you can you should give a lot more credence to this answer).
'near'+'s'='NEARS'
(Other definitions for nears that I've seen before include "is approaching" , "Moves towards" , "Approaches - snare (anag)" , "Saner (anag.)" , "Draws closer to" .)