Lack of practice for play set in USSR (9)

I believe the answer is:

rustiness

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'lack of practice' is the definition.
The definition suggests a singular noun which matches the answer.

'play set in ussr' is the wordplay.
'play' indicates an anagram.
'set'+'in'+'ussr'='setinussr'
'setinussr' is an anagram of 'RUSTINESS'.

'for' acts as a link.

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(Other definitions for rustiness that I've seen before include "being out of date?" , "Condition of being out of practice" , "Discolouration of age" .)

I've seen this clue in the Sydney Morning Herald.

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