A Manc goalie, awfully self-important (11)

I believe the answer is:

egomaniacal

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'self-important' is the definition.
Both the answer and definition are adjectives.
Maybe you can see a link between them that I don't see?

'a manc goalie awfully' is the wordplay.
'awfully' indicates anagramming the letters.
'a'+'manc'+'goalie'='amancgoalie'
'amancgoalie' anagrammed gives 'EGOMANIACAL'.

Can you help me to learn more?

(Another definition for egomaniacal that I've seen is " excessively selfish".)

I've seen this clue in The Times.

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