Dethroned world champion Kimi Raikkonen has confirmed suspicions he struggled with motivation at times during the 2008 season.

The Ferrari driver this year began the defence of his drivers' title strongly, winning two of the first four races.

But Raikkonen, 29, struggled with subsequent developments of the F2008 car, and ultimately finished behind both Lewis Hamilton and his own teammate Felipe Massa in the final classification.

Reports throughout the season queried Kimi's motivation, and he now confirms: "That is the way it is; if you know you are fighting only for third place then you maybe don't have the same speed for the whole race as normal.

"If you have no chance to overtake or improve your position, it is definitely not very interesting," he told the Finnish broadcaster MTV3.

Raikkonen, however, vowed to be in top form next year, when from the first race he will be back in contention for the crown.

"When you are driving for the title, naturally things are completely different," he said.

Ferrari spokesman Luca Colajanni was also quoted by MTV3 as confirming that the 2008 season was a difficult one for Kimi.

But he insisted: "Even when he was in a bad mood, he always behaved professionally."

Source: GMM