Uncertain quantities supplied by eccentric character in remote region (4,5)

I believe the answer is:

wild cards

'uncertain quantities' is the definition.
(a wild card is something unpredictable)

'eccentric character in remote region' is the wordplay.
'eccentric character' becomes 'card' (I've seen this before).
'in' indicates putting letters inside.
'remote region' becomes 'wilds'.
'card' placed within 'wilds' is 'WILD CARDS'.

'supplied by' acts as a link.

(Another definition for wild cards that I've seen is " Maybe competitors in US open".)

I've seen this clue in The Independent.

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