Green bottle may cause upset if struck (3,5)

'cause upset if struck' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'green bottle' is the wordplay.
I cannot quite see how this works, but
'green' could be 'raw' (both can mean naive or inexperienced) and 'raw' is found within the answer.
'bottle' could be 'nerve' (both can mean courage) and 'nerve' is located in the answer.
This accounts for all the letters.
This explanation may well be incorrect...

'may' is the link.

Can you help me to learn more?