Stop that man going inside: needs to be sent back for therapy (5)
I believe the answer is:
rehab
'for therapy' is the definition.
(I've seen this in another clue)
'stop that man going inside needs to be sent back' is the wordplay.
'stop' becomes 'ban' (I've seen this in other clues).
'that man' becomes 'N' (knight, a man in chess).
'going' is a deletion indicator.
'inside needs' becomes 'her' (I can't justify this - if you can you should give a lot more credence to this answer).
'to be sent back' says the letters should be written backwards.
'ban' with 'n' taken away is 'ba'.
'ba'+'her'='baher'
'baher' written backwards gives 'REHAB'.
Can you help me to learn more?
(Other definitions for rehab that I've seen before include "Course of treatment for addicts" , "Rehabilitation (abbrev.)" , "Treatment for alcoholism" , "Treatment for addicts (abbrev.)" , "Process of restoring, eg, an addict to health" .)