The Finn has been drafted into Lotus' 2013 lineup for Austin and Brazil after his Ferrari-bound countryman Raikkonen opted for early back surgery.
After Nico Hulkenberg said no, reportedly also considered for the two-race job was Michael Schumacher.
Lotus driver Romain Grosjean, however, suggested it was never very likely the seven time world champion would make a third F1 comeback.
"It was good marketing," the Frenchman smiled to RMC Sport, "but I would have been quite surprised if he had returned.
"It was not easy when he returned for the first time," added Grosjean. "Now, arriving late in the season for two races in a team he doesn't know — it would have been risky," added Grosjean.
So 'risky', in fact, that German Hulkenberg turned down the chance.
"Of course it was attractive," he said on Thursday. "It sounded attractive from the outside."
The fact Hulkenberg turned down the chance indicates that Lotus was giving him no guarantee that the seat would lead to a full-time role in 2014.
"If I had stepped in, I don't think people would have expected me to beat Romain right away," he said.
So instead of damaging his reputation while getting up to speed, Hulkenberg passed the torch to Kovalainen, whose return to F1 for 2014 seems more secure.
"The only team I've seriously spoken about next year is Caterham," said the Finn. "We're getting close to the point where we're starting to agree the terms.
"This weekend and Brazil won't I think have a huge influence on that," added Kovalainen.
Indeed, Caterham boss Cyril Abiteboul confirmed on Thursday that while the team released Kovalainen to Lotus for Austin and Brazil, the 32-year-old remains "a valued member of the Caterham family".