Kimi Raikkonen says he expected to have a difficult year when returning to Ferrari this season as changes are difficult to make within the team.

Having driven for Lotus for two years following his return to F1, Raikkonen joined Ferrari for a second time at the start of 2014 ahead of the introduction of new power unit regulations. Speaking after the final race in Abu Dhabi which brought to an end a season in which his best result was fourth place, Raikkonen said his struggles had not come as a surprise.

"With the team I expected it to be difficult because I knew how things work and if the car doesn't suit you," Raikkonen said. "I had similar issues before with Ferrari one year and it's not easy to change things when certain things are not right for you, but still we're here and we have a clear plan what we have to improve and what we have to do to get back to where Ferrari should be."

Although talking just before Marco Mattiacci was replaced as team principal, Raikkonen said there had been a lot of progress made to prepare Ferrari for a better 2015 season.

"I feel that the changes that have been made in the team, inside and in all the areas are going to make big, big improvements. It's unfortunate that we have this kind of year because it's not good for me, it's not good for Ferrari or all the fans of Ferrari but that's part of the game.

"It's not the first time that we've had difficult years and you just have to take all the good things out of it and make sure that the things don't happen like have happened this year in the future. I think there's a lot of things to be taking out but obviously the end result is bad. That's how it is."