James Kirtley has been left out of Sussex's squad for their crucial Championship match against Middlesex at Southgate tomorrow.

The 30-year-old has played just three games since re-modelling his bowling action earlier this year, taking seven wickets.

Southgate has a history of helping spinners and the county could play both Mushtaq Ahmed, who has recovered from a sore neck, and Ollie Rayner.

That means one of the seamers is surplus to requirements so Kirtley misses out despite being the most experienced member of their attack. He will play in a second team one-dayer against Surrey at Hove on Friday.

Cricket manager Mark Robinson said: "Leaving out someone of James's experience is always tough, just as it was last week when we left out Robin Martin-Jenkins.

"But we do it in the best interests of Sussex to help us win cricket matches. All the reports are that Southgate will turn so two seamers and one or two all-rounders should be able to do the job. It's horses for courses really."

Skipper Chris Adams' unbroken run of Championship appearances is also under threat Adams has not missed a game since September 2002 - a run of 58 successive Championship matches - but he will need a fitness test before the start of play after suffering a badly bruised thumb on Saturday.

Sussex have no designated vice-captain since Kirtley stepped down at the start of the season.

Matt Prior stood in for a C&G Trophy game last month when Adams was rested and it is likely that he will take charge should Adams be unfit.

Mushtaq's presence in the side is arguably more important than Adams.

Sussex badly missed their prolific leg-spinner, who has taken 53 wickets in eight games this season, when they were held to a draw by Kent at the weekend.

Adams was delighted with Rayner's contribution against Kent when he took 3-89 as Sussex pressed for victory on the final day.

Adams said: "We will certainly take Ollie to Southgate and see what the pitch is like. He is an option. He bats, is a good fielder and three-dimensional cricketers like him are what we are looking for."

Rayner was thrilled to take his first first-class wickets against Kent and would love to form part of a two-pronged spin attack against Middlesex.

He said: "That would be superb. People have to accept that I'm never going to be as prolific as Mushy but I think I showed against Kent that I can do a job in my own right as a spinner."