Cheer when you hear the team's a man short? (7)
I believe the answer is:
hearten
'cheer when' is the definition.
'hearten' can be an answer for 'cheer' (synonyms). I am unsure of the 'when' bit.
'hear the team's a man short?' is the wordplay.
'hear' becomes 'heart' (I can't justify this - if you can you should believe this answer much more).
'the team' becomes 'men' (group of people).
'a man' becomes 'm' (M is an abbreviation for male or masculine).
'short?' is a deletion indicator (short can mean missing or absent).
'men' with 'm' taken out is 'en'.
'heart'+'en'='HEARTEN'
'you' is the link.
Can you help me to learn more?
(Other definitions for hearten that I've seen before include "Make (someone) more confident" , "given cheer" , "Comfort" , "Be encouraged" , "Make cheerful" .)