Man in Elgin losing marbles? (5)

I believe the answer is:

nigel

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

'man' is the definition.

'elgin losing marbles?' is the wordplay.
'elgin' can be anagrammed to 'NIGEL'.
Though, I'm not sure how this is indicated.

'in' is the link.

Can you help me to learn more?

(Other definitions for nigel that I've seen before include "Sir - - Hawthorne, actor" , "First name of the leader of the Brexit Party since 2019" , "-- Gresley, railway engineer" , "--- Pargetter, (Archers)" , "boy" .)

I've seen this clue in The Sun.

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