Jason Lewry will be out of the Sussex bowling attack for three weeks because he needs surgery on his injured knee.

The left-armer suffered a small tear in the back of his right knee while he warmed-up for last Sunday's totesport League match at Derby.

A scan on Monday revealed the extent of the problem and he will undergo keyhole surgery later this week.

Director of cricket Peter Moores said: "We could have just left it ten days to settle down, but the surgery will clear it up for good and he should be back within three weeks, maybe earlier.

"Next week we have another break so he might not miss too many matches."

Lewry's absence means Mohammad Akram will share the new ball with James Kirtley at the County Ground tonight when the Sharks take on Nottinghamshire Outlaws in the totesport League (4.10pm).

Three wins in their last five completed games in the 45-overs format mean Sussex could move to within four points of Yorkshire, who currently fill the third promotion spot in the second division, with victory against an Outlaws team who were seven-wicket winners when the teams met at Trent Bridge at the end of May.

South African born batsman Kevin Pietersen, who qualifies for England at the end of the season, is Notts' dangerman.