Updated

London, England (SportsNetwork.com) - Lotus revealed on Sunday that Kimi Raikkonen will not compete in the final two Formula One grand prix this season after deciding to undergo back surgery later this week.

The team also said it will make an announcement about Raikkonen's replacement for the Nov. 17 United States Grand Prix in Austin, Texas and the Nov. 24 Brazilian Grand Prix in Sao Paulo "in due course."

Raikkonen, the 2007 F1 world champion, has been suffering back problems during the second half of this season and nearly had to sit out the Sept. 22 Singapore Grand Prix due to severe pain. The 34-year-old Finn has opted to have surgery now so his 2014 season will not be impacted. He will drive for Ferrari next year.

"In an ideal world, it would have been nice to finish the season with Lotus," Raikkonen's manager, Steve Robertson, told Finnish newspaper Turun Sanomat. "However, due to the severe pain that Kimi is having, sadly it is not possible."

There is speculation that Lotus will select either Davide Valsecchi or Jerome D'Ambrosio, both of whom are reserve and test drivers for the team, as the substitute for Raikkonen. Valsecchi has no F1 race experience. He is the 2012 GP2 Series champion. D'Ambrosio has 20 grand prix starts to his credit.

Raikkonen has been in a pay dispute with Lotus, claiming the team has yet to compensate him this season. He had threatened to not compete in the USGP and Brazilian GP unless he received payment.

Last week in Abu Dhabi, Raikkonen had his race come to an end on the first lap when he sustained damage to his front suspension. He had to start from the back of the grid since he was excluded from qualifying. His Lotus failed a post-qualifying floor deflection test.