Prior to miss Twenty20 finals day

Prior is to be kept in cotton wool until the big match at The Oval

Sussex must cope without England wicketkeeper Matt Prior for Twenty20 finals day at Edgbaston on Saturday.

The England and Wales Cricket Board (ECB) want Prior to be rested from all cricket leading up to the Ashes decider starting on 20 August at The Oval.

Prior suffered a back spasm moments before the toss in the fourth Test, but battled through the defeat in Leeds.

However, he was then rested as Sussex beat Worcestershire by eight wickets at Hove inside three days on Thursday.

In a statement the ECB said it was "extremely grateful to Sussex for their co-operation and understanding in relation to this matter".

Prior told BBC Radio 5 live: "It's not a precaution for any injury or anything like that. The back's absolutely fine now."

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He refused to be drawn on the hot issue of team selection for The Oval, but added: "The 11 guys who go out there next Thursday will be absolutely up for it.

"It's like having a final within a Test series, it's so exciting. The whole country has been gripped by the Ashes and really got behind us."

The Oval's flat wicket is tipped to help the batsmen more than the bowlers, but Prior said: "The way the bowlers have bowled all series has been absolutely fantastic. We know we've got the bowling unit and we'll be very confident."

Sussex were losing semi-finalists in the 2007 Twenty20 Cup, and can go one better if they beat Northants on Saturday.

Victory would take them into a final against either Kent and Somerset, who have each won the cup once. In Prior's absence, Ben Brown and Andrew Hodd will challenge for the gloves.