Trescothick has had his problems in the last 18 months

The Somerset star came home early from Australia with a stress-related illness but is now back in form for his county.

Chris Schofield - in minor counties cricket last year - and Darren Maddy return after a seven-year absence.

Uncapped Essex opener Mark Pettini and Sussex all-rounder Luke Wright are also in, but Andrew Strauss misses out.

Interview: Marcus Trescothick

The final 15 for the tournament in South Africa, which starts on 11 September, will be named from the squad of 30 by 11 August.

And it is by no means certain that Trescothick will make the cut after a difficult 18 months.

The 31-year-old left-hander flew home early from India in February 2006, and had a patchy season with the bat last season before being rested for the Champions Trophy.

We will not be placing undue pressure on him to return to international cricket without first carefully considering all the issues England chairman of selectors David Graveney

Trescothick also missed the World Cup but has rediscovered his best form for his county this season while England's top-order batting misfired in the Caribbean and in the home one-day series against West Indies.

"As it stands nothing has been set in concrete, it's just an opportunity for us to take our time," he told BBC Sport.

"I'm just enjoying my cricket here and we'll continue to see how it goes over the next couple of months.

"I can only judge between now and 11 August whether I'm fit to tour again and at this moment it's given us an opportunity to say if I feel things have progessed we can maybe think about it."

MESSAGEBOARD Can England really take to South Africa a man who came home early from India, sat out the Champions Trophy and World Cup, and left the Ashes tour nine days before the first Test? Paresh Soni - BBC Sport Message board: Have your say

Chairman of selectors David Graveney, who has been in regular contact with him during his troubles, said: "We are pleased that Marcus has made a successful return to county cricket this summer and he remains a world-class opening batsman.

"But we will not be placing undue pressure on him to make a return to international cricket without first carefully considering all the issues involved.

"Ultimately, we will be guided by Marcus and the ECB medical staff as to his availability and I would anticipate that further discussions will take place with him before the squad is narrowed down."

Schofield secured his Surrey deal after a successful trial

Schofield has been rewarded after becoming the leading wicket-taker in the Twenty20 Cup this season with 17 victims in eight matches.

He played two Tests in 2000 against Zimbabwe but was released by Lancashire in 2004 and began 2006 with minor county Suffolk.

A successful trial with Surrey at the back end of last season led to a one-year contract.

"I am very surprised. I had a very good start to the season with the one-day stuff but to get a call-up so early in trying to get back into cricket has been fantastic," the 31-year-old told the BBC.

"Having two years out of the game playing minor counties with Cheshire and Suffolk has made me find my bowling again which I needed to do to play first-class cricket.

"My main objective this year was to play as well as I could with Surrey, try to get an extension on my contract, and maybe two or three years down the line, if I'm playing regular first-team cricket, England may be there but for it to come so early is fantastic."

Maddy is the most prolific batsman in the brief history of the shortened format and has continued the form he showed with Leicestershire after moving to Warwickshire.

Experienced seamers James Kirtley and Glen Chapple and spinner Jeremy Snape, who like Maddy are all in their thirties, are three others to be brought back in from the cold.

Jamie Dalrymple, Ed Joyce and the injured Saj Mahmood are three others who went to the Caribbean who are missing from the provisional line-up but veteran opener Mal Loye and 36-year-old wicket-keeper Paul Nixon make the squad after missing the series against West Indies.

England provisional 30-man squad for Twenty20 World Cup: