It's abrasive when football manager meets directors (5,5)

I believe the answer is:

emery board

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

'it's abrasive' is the definition.
(I've seen this before)

'football manager meets directors' is the wordplay.
'football manager' becomes 'emery' (I am not sure about this - if you are sure you should believe this answer much more).
'meets' is a charade indicator (letters next to each other).
'directors' becomes 'board' (I've seen this before).
'emery'+'board'='EMERY BOARD'

'when' acts as a link.

Can you help me to learn more?

(Another definition for emery board that I've seen is " Abrasive".)

I've seen this clue in The Telegraph.

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.