Caterham subsequently decided to give its 2014 race drives to Kamui Kobayashi and Marcus Ericsson, and team chief Tony Fernandes admitted that Kovalainen's Lotus performances had helped swing the decision against him.
"Obviously we would lie if that we said it didn't play a part," Fernandes said.
"It was a whole mixture of a lot of things but in any decision there are pros and cons.
"I am egalitarian, I put it out to various team members - there were those pro Heikki and those pro Kamui and I had to make a choice."
Fernandes admitted it had been a "cold" process parting with Kovalainen after his role in the team's growth.
"We have to move on, we have to be a little bit cold, if we want to be successful," he said.