Yorkshire's Director of Cricket, David Byas, is mulling over whether to sign another overseas player to see out the rest of the season now that Australia have named both Darren Lehmann and Ian Harvey in their 14-man one-day squad.

Their inclusion for the Videcon Cup tournament in Amsterdam from August 21, followed by the ICC Champions Trophy in this country during September, means Yorkshire will be without the pair from the middle of this month.

Yorkshire knew that Lehmann was an automatic choice but the selection of Harvey has taken them by surprise in view of his poor form for the county since returning from a hamstring injury.

Harvey remains a hugely gifted player, which is why Australia are keeping faith with him, and Byas was hopeful that an avalanche of runs and a sackful of wickets was just around the corner.

"Everyone goes through a bad patch and Harvey is no exception," said Byas.

"If he had remained with us, there was every chance that he would have shaken off his indifferent run of form and ended the season with a bang."

Lehmann and Harvey will be available for Yorkshire for the final time on August 18, when they play Leicestershire in a totesport League day-night match at Grace Road. Their fellow Australian, Phil Jaques, returns to Headingley on August 15 and stays until the end of the campaign.

Jaques has already proved his worth with 662 Championship runs in six matches and he is still Yorkshire's leading run-scorer in the competition.

Harvey's bowling has been an even bigger disappointment than his batting, his four Championship wickets coming at a cost of 91 apiece, and if Byas does sign someone it should be an out-and-out fast bowler, if one is available at such short notice.

"There has been no time yet to consider whether we would benefit from a replacement but I will be giving it a lot of thought over the next few days," said Byas.

Yorkshire resume their Championship programme next week when Derbyshire visit Headingley on the Thursday and this will be the only one of the six remaining matches in the competition that Lehmann and Harvey will be able to play in.

Lehmann missed out last week with an inflamed disc in his back but Byas said that he was now well on the way to recovery.

"He travelled to Southgate on Sunday for the totesport League game with Middlesex but was still not fully fit and it would have put him back a fortnight had he played," said Byas.