Young for the team (7)
I believe the answer is:
fifteen
'team' is the definition.
(I've seen this before)
'young' is the wordplay.
I cannot really understand how this works, but
'young' could be 'teen' (similar in meaning) and 'teen' is found in the answer.
This explanation may well be incorrect...
'for the' acts as a link.
Can you help me to learn more?
(Other definitions for fifteen that I've seen before include "No. of men on dead man's chest (Stevenson)" , "Square root of two hundred and twenty-five" , "Longish odds - 7" , "... number" , "Product of two primes" .)