Posh interrupting a group of footballers before international - tip for team is familiar (2,4)
I believe the answer is:
au fait
'familiar' is the definition.
(I've seen this before)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for au fait that I've seen before include "'Having a good knowledge of (2,4)'" , "Well acquainted with, knowledgeable about" , "Being up to date in the knowledge required" , "Familiar with - in France" , "Well-acquainted (with)" .)