Raikkonen announced at the weekend he would not be competing in the United States this weekend or Brazil next, instead opting to undergo surgery for a long-standing back problem.
That has left team principal Eric Boullier with precious little time to find someone to step in and fill the 34-year-old's shoes.
Fellow Finn Kovalainen, however, has answered the call and is now set to compete in his first grand prix for almost a year since being axed by Caterham after the final race of last season.
The 32-year-old, who started his career at Enstone - Lotus' current home - in 2007 when the team were known as Renault, has been keeping himself in shape with six Friday morning practice workouts this year for Caterham.
Boullier has been forced to turn to Kovalainen after failing to land first-choice in Sauber's Nico Hulkenberg for contractual reasons.
Hulkenberg is due to sign for Lotus from next year providing the team can finally resolve its financial issues which resulted in Raikkonen failing to be paid any of his salary up until the last race in Abu Dhabi.
With Lotus still firmly in the hunt for either second or third in the constructors' championship - trailing Mercedes by 37 points and Ferrari by 26 - Boullier also resisted the opportunity to place reserve Davide Valsecchi in the car.
Valsecchi has barely turned a wheel in anger since winning the GP2 title last year, but with millions of pounds at stake, it is understood Boullier could not gamble on his inexperience at this stage.