Asian coach expressed close control (5,4)

I believe the answer is:

tight rein

I'm a little stuck... Click here to teach me more about this clue!

'asian coach expressed' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'close control' is the wordplay.
I cannot quite understand how this works, but
'close' could be 'tight' (synonyms) and 'tight' is found in the answer.
'control' could be 'rein' (synonyms) and 'rein' is present in the answer.
No letters remain.
This explanation may well be incorrect...

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.