Maybe ensure no shooting from football team without right back (5)
I believe the answer is:
unarm
'maybe ensure no shooting' is the definition.
(remove a gun)
'football team without right back' is the wordplay.
'football team' becomes 'man u' (short for Manchester United).
'without' means one lot of letters goes inside another ('without' can be similar in meaning to 'outside').
'right' becomes 'r' (common abbreviation).
'back' says the letters should be written backwards.
'manu' enclosing 'r' is 'mranu'.
'mranu' backwards is 'UNARM'.
'from' acts as a link.
(Other definitions for unarm that I've seen before include "Deprive of all weapons" , "Remove weaponry from" , "Render harmless" , "Take weapons from (someone)" , "Disable" .)