Caterham team principal Tony Fernandes admits Heikki Kovalainen's performances for Lotus at the end of 2013 hurt his chances for 2014.

Kovalainen appeared close to a return to Caterham towards the end of last season, speaking openly about talks with the team. However, when Kimi Raikkonen was ruled out of the last two grands prix of the year, Lotus opted to sign Kovalainen as it chased third place in the constructors' championship.

However, Kovalainen failed to score a point in either of the final two races - finishing 14th on both occasions - while team-mate Romain Grosjean was second in Austin. With Kovalainen suffering such a disappointing end to the year, Fernandes admitted those drives had impacted on his decision to opt for Kamui Kobayashi as the Caterham's experienced driver in 2014.

"Obviously we would lie if that didn't play a part," Fernandes said. "There was a whole mixture of a lot of things, but yes. In any decision there are pros and cons and I'm very egalitarian - maybe too egalitarian - so I put it out to the various team members in the F1 team and there were those who were pro for Heikki and those who were pro for Kamui.

We put it all together and finally I had to make a choice and I made the choice of Kamui."

However, Fernandes said it had been far from easy to drop Kovalainen from his plans.

"It was a hard decision. We're the last of the teams to announce their drivers but we have to move on and we have to be a little bit cold if we want to be successful. We have to weigh up so many different facets and this was the right decision that we chose. Time will tell if that's the right decision overall."