Lotus approached Michael Schumacher about making a possible Formula One comeback in the last two races of the season but the retired seven times world champion made it clear he was not interested.
Schumacher's spokeswoman Sabine Kehm said the approach to the 44-year-old, who quit the sport last year after a three-year comeback with Mercedes following his earlier retirement from Ferrari, came as no surprise.
"Michael's performance against Nico (Rosberg last year) and Nico's performance against Lewis (Hamilton this year) made a lot of people aware of how good Michael still was," she told Reuters in an email on Wednesday.
"Plus, he is still very fit. But he just feels so good in his new life."
Lotus have been seeking a replacement for 2007 champion Kimi Raikkonen, who is leaving for Ferrari at the end of the year and has pulled out of the U.S. and Brazilian Grands Prix to have back surgery.
They are now expected to agree a deal with former Renault, McLaren and Caterham driver Heikki Kovalainen at the US Grand Prix in Austin, Texas.