Recent improvement in the middle (6)

I believe the answer is:

centre

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'the middle' is the definition.
(synonyms)

'recent improvement' is the wordplay.
'recent' anagrams to 'CENTRE'.
However, I am not sure how this is indicated.

'in' acts as a link.

Can you help me to learn more?

(Other definitions for centre that I've seen before include "The point equidistant from everything" , "Recent (anag)" , "Heart" , "Middle, hub" , "See 1" .)

I've seen this clue in The Daily Express.

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