Notably tense and ready to play (5,2)

I believe the answer is:

keyed up

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'notably tense' is the definition.
'keyed up' can be an answer for 'tense' (I've seen this in another clue). I'm unsure of the 'notably' bit.

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for keyed up that I've seen before include "On tenterhooks" , "Tense and nervous" , "Tense and excited" .)

I've seen this clue in the Evening Standard.

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