Lotus driver Kimi Raikkonen will not take part in the last two races - US and Brazilian Grands Prix - of the 2013 Formula One season after deciding to undergo back surgery next week. Raikkonen has a long-standing back problem, which flared up during the Singapore GP in September.
"In an ideal world it would have been nice to finish the season with Lotus," Raikkonen's manager Steve Robertson told autosport.com.
"However, due to the severe pain that Kimi is having, sadly it is not possible," he said.
Meanwhile, Raikkonen also complained that he had not been paid by cash-trapped Lotus before this month's Abu Dhabi Grand Prix. The 'Iceman' told reporters he had considered not attending that race.
He had a racing stint in the World Rally Championship before returning to F1 with Lotus last year and has so far won two races with the team. In Abu Dhabi last weekend, Raikkonen said he may not take part in the final two races of the season if Lotus do not fulfill a promise to solve a financial dispute.
The 34-year-old, who decided to race in Abu Dhabi at the last minute, said he has "not been paid a single euro all year".
The Finn had visited Ferrari for a seat fitting ahead of his return to the team next season and also met with team principal Stefano Domenicali on Thursday.
Raikkonen, who won the 2007 world championship with the Italian-based side, last drove for them in 2009.