Sports outfit found in first armoire on the left? (4)

'sports outfit' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'found in first armoire on the left?' is the wordplay.
'first' suggests taking the first letters.
'armoire' becomes 'af' (I am not sure about this - if you are sure you should believe this answer much more).
'on' indicates putting letters inside (as in clothing 'on' a person).
'the left?' shows that the letters should be reversed in order.
The initial letters of 'found in' is 'fi'.
'fi' placed within 'af' is 'afif'.
'afif' back-to-front is 'FIFA'.

Can you help me to learn more?