Ferrari's engineers have voiced concerns about Kimi Raikkonen's ability to develop a car with the skill of Michael Schumacher and want the German to test their new 2007 charger over the winter.

Following his retirement, Schumacher confirmed that he would be staying with the team in an as-yet-unspecified role. While that wasn't expected to be as a test driver, the proposal has been put forward by Luca Baldisserri, Ferrari's chief race engineer.

"I've already asked [Jean] Todt and to convince him to test our cars. After all, driving is the thing he loves most," Baldisserri told the Italian press.

"Schumacher has been with us for 11 years and I can say he's brought everything we have now: he's given us precious suggestions on work methods and he's been a role model not only at the wheel, but also in his professional approach."

"It will be a big problem to carry on at the same level without him."

Those sentiments were echoed by race and test technical manager Nigel Stepney.

"It will be a difficult winter," the Englishman admitted. "We are losing what has been for us the focal point all these years.