County champions Yorkshire have begun a frantic search for an overseas player to cover for new captain Darren Lehmann if he should be unavailable for the first few matches of the new season.

Cricket chairman Bob Platt said that four names are being considered, but he declined to give further details at this stage.

Alarm bells started ringing at Headingley as soon as it was announced that Australia had called up Lehmann for the three-Test tour of South Africa which starts next month.

If he does well in South Africa, Lehmann could also be wanted for Australia's tour of Zimbabwe from April 13 to May 7, which would mean him at least missing Yorkshire's five Benson and Hedges Cup zonal matches and the tough opening Championship games against previous holders Surrey and Somerset.

Platt revealed that if Lehmann is absent at the start of the season it had been agreed that Michael Vaughan would lead the side - provided England allow him to play.

"As Vaughan is a batsman, I don't think England will want to rest him, but if they do then we will have to cross that bridge when we come to it," said Platt.

Lehmann, 31, has so far played in only five Tests - and 69 one-day internationals - for Australia, despite becoming their heaviest run-scorer of all time in Sheffield Shield cricket and consistently piling up runs both for Yorkshire and South Australia in recent years.

He has not played Test cricket for three years, but chairman of selectors Trevor Hohns said that since then Lehmann had done everything required of him.

"He has dominated domestic cricket and fully deserves his chance to represent Australia at Test level again," said Hohns.

"We took into account his experience and leadership and felt that he can make a genuine contribution to the touring party."

With several countries involved in Test matches during April-May, Yorkshire are probably looking in the direction of New Zealand, South Africa and Pakistan to find a replacement for Lehmann if one is necessary.

"We need to find our man and then put things on hold until we know for sure that Lehmann will be missing," said Platt.

"It is a very tough start to the season and he couldn't be away at a worse time. It is essential that we have a suitable replacement in reserve."

England's performance director, Hugh Morris, is waiting for Yorkshire's Ryan Sidebottom to return from holiday before being invited to join the England National Academy squad in Australia for the last six or seven weeks of their stay.

"Ryan's dad Arnie, the county's coach and former fast bowler, said: "Morris contacted Yorkshire to tell Ryan that he was needed as a replacement for someone who had broken down, but he is currently in Tenerife.

"He arrives home at the weekend and the news should be a nice surprise for him."

Updated: 11:41 Thursday, January 31, 2002