Sussex Sharks are sniffing promotion after producing their best run of one-day form for five years.

The county reeled off a fourth successive win in the totesport League against Scottish Saltires on Sunday, their best sequence since they won promotion as champions of Division Two in 1999.

But director of cricket Peter Moores admits they can not afford a slip-up in any of their remaining three games, starting under the Hove lights against Worcestershire Royals tonight (4.10).

The county go to Durham on Sunday week before playing champions-elect Middlesex under the lights on September 2 in their last match.

Middlesex are favourites to win the title, but Worcestershire's 83-run win at Lord's on Sunday lifted them into second place.

Five counties are battling to fill the third promotion spot, but Moores believes Sussex will be hard to overtake if they stay unbeaten, especially after they gave their run rate a significant boost with Sunday's 114-run win in Edinburgh.

"It sets things up really well, it's a big game for both teams," said Moores.

"Worcestershire will fancy their chances after winning on Sunday, but we are playing really good one-day cricket at the moment and home advantage can make a difference.

"The run we've been on has kept us bubbling. That tends to happen when you know that if you lose you are almost certainly out of the running. But there are quite a few sides who can't really afford to lose another game like us."

The key to Sussex's big wins over the Scots and Derbyshire in the last week has been the form of Michael Yardy and he will have another crucial role tonight.

The left-hander followed his unbeaten 88 against Derbyshire with 83 on Sunday when he opened the innings in place of Ian Ward.

Ward is ruled out again tonight because of a groin strain and will have intensive treatment over the next couple of days to try to be fit for Thursday's Championship match between the two sides.

"Yards is playing so well at the moment," added Moores. "Having him at the top means we still have our left and right-handed combination while Carl Hopkinson, who came in for Wardy on Sunday, lifts our fielding which is obviously another key area."

Worcestershire will be without their England fast bowler Kabir Ali who was having a scan yesterday after tearing stomach muscles against Middlesex. His place goes to Nadeem Malik.

Wicketkeeper Steve Rhodes, who retires at the end of the season, will lead the side until then following the surprise resignation of Ben Smith last week .

Worcestershire will include the prolific Graeme Hick, who is in form having scored 120 on Sunday against Middlesex at Lord's.

Sussex will be providing free coaching for under-14s in a specially designated family area at the Cromwell Road end of the ground tonight.