Sussex are fighting to keep their first-choice bowling attack together for the Championship run-in.

Leading wicket-taker Jason Lewry, already out with a side strain, is suffering from Gilmore's Groin and will undergo surgery tomorrow.

He will be missing for at least a month.

And now the county are trying to keep Pakistani Rana Naved for the all their remaining matches after he was called up for the Asia v Africa, ICCbacked, one-day competition in South Africa later this month.The three-match series takes place between August 17-21 which means Naved would miss the Championship fixture against Middlesex at Lord's and the totesport League game against Leicestershire.

Skipper Chris Adams admitted the loss of Lewry, who has taken 42 first-class wickets this season including four five-fors, is a big blow.

Sussex hope to have him available for their last two Championship games against Glamorgan and Kent.

He said: "It's not ideal. We're disappointed because he's been outstanding this year and he's devastated because he was hoping to be the first bowler to 50 wickets."

Sussex have a written assurance from the Pakistan Cricket Board that Naved would be available for the rest of the season.

They were checking today to see if that promise still holds good.

The 27-year-old has taken 16 wickets in three Championship appearances including a season's best 4-26 in last week's draw against Gloucestershire.

Director of cricket Peter Moores said: "We're finding out how the PCB view this tournament. If the right people felt it that going would improve his international career then we would think seriously about letting him go.

If we felt it wouldn't he'd stay. "We will do what is best for the player but my gut feeling is that we'll have Rana all the time."

Surrey visit Hove today (11am), a match that Adams says Sussex must win if they are to retain any chance of challenging for the title.

"It's very tight and our last two games could have gone a lot better," he said.

"Losing to Hampshire was tough because I didn't think we deserved to. I thought we performed well against Gloucestershire but you're going to have to play brilliantly to win a game when 137 overs are lost because of the weather. The title is still on for us if we get on a roll but I think we'd have to win four out of the last six.

"If we can just get a few things going our way for once we will be in great shape but if we don't we could find ourselves in a real scrap.

"We're betwixt and between at the moment. If we beat Surrey we are in a great position to make a charge, if we lose we will have to fight our way out of a hole."

Robin Martin-Jenkins will replace Lewry after being left out of the last two Championship matches but Ian Ward (torn groin) misses a reunion against his former county.

Off-spinner Mark Davis is also out for another week with a dislocated finger while Tim Ambrose will play despite bruising a shoulder during Monday's totesport League win over Somerset. Carl Hopkinson has been added to the squad as a precaution.

Moores added: "We've been in the bottom three for quite a while and it's time to make a move. Make no bones, the first division is a proper scrap whether you're fighting to win it or stay in it. But the first step is to get out of the relegation zone by beating Surrey and putting them into the mire."

Surrey have injury problems of their own with Mark Butcher (wrist), Martin Bicknell (Achilles) and James Ormond (hand) all missing.

Jade Dernbach, a 19-yearold seamer, is poised to make his Championship debut.

Former England player Chris Schofield plays for Sussex against Surrey in the 2nd XI Championship at Stirlands CC today (11am). The 26- year-old leg spinner is on trial with the county.

Sussex: Montgomerie, Prior, Yardy, Goodwin, Adams (capt), Ambrose or Hopkinson, Martin-Jenkins, Wright, Rana Naved, Mushtaq Ahmed, Kirtley. Surrey: Clinton, Newman, Ramprakash (capt), Clarke, Batty, Brown, Azhar Mahmood, Murtagh, Doshi, Akram, Dernback or Salisbury.