Former F1 racer - and team co-owner - Gerhard Berger says he wouldn't have signed Kimi Raikkonen for the 2012 season.

Berger, who was involved with both BMW Sauber and Toro Rosso after the end of his racing career, questioned whether or not Lotus Renault have made the right decision in giving the 2008 title winner the chance to make a return to the sport after two years competing in the WRC.

While many have welcomed the announcement of Raikkonen's return, Berger was more cautious as he insisted he wouldn't have made the same decision as Lotus Renault team boss Eric Boullier.

"I would say it is 50/50 if he is able to reach the top again," Berger was quoted as telling Austrian broadcaster ORF. "I would be surprised if he has the strength, discipline and ambition to return to the front.

"Of course he should not be underestimated and I don't underestimate him - there is no question he is quick and it would be good for F1, so let's hope for it and wish him all the best.

"[However] I would not have taken him. Formula One is so unique. If you don't really live it day and night, constantly perfecting yourself and working on it, it is difficult.

"It's hard, hard work, and whether he has the willingness to do this hard, hard work, we'll see."