He has a new role _ a key part (5)

I believe the answer is:

leroy

I'm a little stuck... Click here to teach me more about this clue!

'he' is the definition.

'a new role a key part' is the wordplay.
I cannot quite understand how this works, but
an anagram of 'role' is 'lero' which is present in the answer.
A single letter 'y' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...

'has' acts as a link.

Can you help me to learn more?

I've seen this clue in the Evening Standard.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.