McLaren are in no rush to sign a successor to departed double world champion Fernando Alonso, the Formula One team's Chief Executive Martin Whitmarsh said on Monday.
However, Germany's Ralf Schumacher, now a free agent after leaving Toyota, can be ruled out of the reckoning.
"Until the second McLaren drive is sorted out I don't think you'll see much movement (in the driver market), so we're not really hurried," Whitmarsh told the Guardian.
"Obviously there are some drivers who've approached us who are contracted elsewhere and we've had to say we can't talk to them unless they can prove they are free to negotiate," added the Briton.
McLaren, who won eight of this year's 17 races, parted with Alonso on Friday after a breakdown in relations between the Spaniard and the Mercedes-powered team.
The vacancy, as team mate to Lewis Hamilton, is the most desirable still to be filled on the 2008 Formula One starting grid and Germany's Nico Rosberg is considered a favourite to fill it.
However, Rosberg, son of 1982 champion and former McLaren driver Keke, is under contract to Williams.
Schumacher, the younger brother of Ferrari's retired seven-times world champion Michael, left Toyota at the end of the season without announcing his plans for 2008.
The Guardian said the German's manager had approached McLaren boss Ron Dennis about possible opportunities but "it was quickly made clear he would not be on the list".
Others linked with the McLaren drive include Finland's Heikki Kovalainen and German rookie Adrian Sutil, who raced for Renault and Spyker respectively this year.
McLaren can also fall back on experienced Spanish test driver Pedro de la Rosa, who last raced for the team in 2006 as a replacement for Colombian Juan Pablo Montoya and finished second in that year's Hungarian Grand Prix.
