It’s silly to exclude me from the game again! (4)
I believe the answer is:
gaga
'it's silly' is the definition.
(thesaurus)
'me from the game again' is the wordplay.
'from' indicates named letters should be taken away.
'again' becomes 'ga' (I can't explain this - if you can you should believe this answer much more).
'game' with 'me' taken away is 'ga'.
'ga'+'ga'='GAGA'
'to exclude' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for gaga that I've seen before include "In senile dotage" , "Slang for crazy - apply a gag" , "fatuous?" , "dotty" , "Barmy joke, third in cracker" .)