McLaren are considering a surprise move for Kimi Raikkonen if Fernando Alonso quits the failing British team.
Alonso is out of contract at the end of the season and McLaren have put together a contingency plan if they cannot persuade the Spaniard to stay.
Press Association Sport understands that Ferrari's Raikkonen, who won nine races and twice finished as a runner-up in the championship for the Woking team between 2002 and 2006, is on their shortlist.
Raikkonen, 38, may be surplus to requirements by Ferrari at the end of the year if the Scuderia choose to hire the highly-regarded rookie Charles Leclerc, who again impressed for Sauber at last weekend's French Grand Prix.
McLaren's British teenage reserve driver Lando Norris is believed to be edging closer to a full-time seat next year, and the team want him to join Alonso.
But Alonso, 36, is considering his options and may choose to turn his back on the sport. Mercedes, Ferrari and Red Bull are not interested in signing the Spaniard, which would make a move to another F1 team appear highly unlikely.
If Alonso leaves McLaren, it is understood that the British team would like an experienced, and marketable driver to partner Norris, 18, and after a bold swoop for Red Bull's Daniel Ricciardo, Raikkonen is an option to fill that void.
McLaren would be able to afford Raikkonen's £10million-a year wages, and a switch back to his former team might appeal to the veteran Finnish driver, who is effectively Sebastian Vettel's number two at Ferrari.
Raikkonen, who has competed in 281 grands prix and clinched the world championship for Ferrari in 2007, has not won a race in more than five years. He is fifth in the championship, 48 points behind Vettel.
A McLaren spokesperson told Press Association Sport: "We don't discuss driver matters."
Belgian driver Stoffel Vandoorne, who is in his second season at McLaren after he replaced Jenson Button, could be the fall guy. Vandoorne, 26, has been out-qualified by Alonso at every race this season.
Alonso called McLaren's display in France last week the team's worst of the year. He retired with a suspension problem on the penultimate lap after qualifying only 16th.
Alonso is in the fourth season of his second stint at McLaren, but despite promises of improvement following their switch from Honda to Renault engines, they are falling back down the grid.
He took aim at McLaren over the radio in last Sunday's race.
"I have no tyres, no brakes, and I am out of the points," he said. "I am trying to do whatever. I don't care too much."
He added afterwards: "This was by far the worst performance of the year. I really hope it is a one-off and not the normality."
Alonso will be back in action at Sunday's Austrian Grand Prix, the second instalment of F1's first triple-header, with Silverstone to follow next weekend.