Blades score midway through — no way back for Arsenal (4)
I believe the answer is:
oars
'blades' is the definition.
(blade is the word of an oar in competitive rowing)
'through no way back for arsenal' is the wordplay.
'through' means one lot of letters goes inside another (some letters go through others).
'no' becomes 'O' (resembles 0 - 'no' can mean 'zero').
'way' becomes 's' (Compass direction - South).
'back for' says the letters should be written in reverse (I've seen 'backing for' mean this).
'arsenal' becomes 'RA' (Royal Artillery).
'ra' in reverse letter order is 'ar'.
'o'+'s'='os'
'os' placed around 'ar' is 'OARS'.
'score midway' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for oars that I've seen before include "Sweeps" , "Sculls" , "Rowing blades" , "Indirectly, they make waves" , "Soar around the rowers" .)