Kimi Raikkonen's back pain issue in Singapore has its roots in an injury from a 2001 crash, AUTOSPORT has learned.
The Finn had a heavy testing accident at Magny-Cours in September 2001, during his rookie Formula 1 season with Sauber.
Raikkonen went off at the fast Imola chicane leading to the Chateau d'Eau corner and had a violent rearward impact.
He was taken to hospital for a precautionary check-up, and though he escaped serious injury, his back trouble is a legacy of that incident.
In Singapore this weekend Lotus got reserve driver Davide Valsecchi ready in case Raikkonen could not drive in qualifying.
He was able to participate but only managed 13th on the grid.
Raikkonen has now returned to his hotel to rest before the race.
Although the back problem remained an issue in qualifying, Raikkonen felt it had eased since final practice earlier in the day.