Kimi Raikkonen's former race engineers all say that the Finn deserves to have kept his Ferrari seat for 2017.

With younger chargers like Valtteri Bottas, Sergio Perez, Nico Hulkenberg and Carlos Sainz all pushing to step up, many were surprised when the Maranello team elected to keep Raikkonen, who in two months will turn 37.

Yet Mark Slade, who worked with Raikkonen at McLaren and Lotus, told Turun Sanomat: "No, [the 2017 deal] wasn't a massive surprise.

"Kimi seems to be in a good situation with Sebastian Vettel, and I believe that a happy atmosphere will help Ferrari to perform.

"Whenever you look to change driver, you need to be sure you're getting something better."

Australian Chris Dyer, who won the title with Raikkonen in 2007 and now works at Renault, agrees.

"From the outside, Kimi does not seem to have changed from the driver I knew from nine years ago," he said.

"He has always been able to do great results when the car and the conditions suit him.

"This season, he has been with Vettel in pace, even when the car is not working all that well - which in the past was maybe not always Kimi's strength."

Andrea Stella, who worked with Kimi at Ferrari in 2008 and 2009 and is now at McLaren, said: "I am not surprised that Kimi is continuing. To me, he seems to be the same.

"He is still a strong racing driver. I think he has even improved since last year."

Raikkonen is fourth in the driver ranking ahead of tomorrow's Belgian Grand Prix.