Raikkonen has been roundly beaten by team-mate Fernando Alonso this season. The Spaniard, who is 8-2 up in qualifying and has finished all 10 races ahead of the 2007 World Champion, sits fourth in the drivers’ standings on 97 points, while Raikkonen is languishing in 12th on just 19.
Following last weekend’s German Grand Prix - which saw Alonso finish fifth while Raikkonen came home 11th and a lap down - the Spanish driver directed a thinly-veiled criticism at his team-mate.
"We have only been able to count on one car again,” he said after the Hockenheim contest, “and we have to improve on that."
However Ferrari boss Mattiacci, who took the role following Stefano Domenicali’s resignation in April, has now publicly backed the Finn.
"Kimi is the driver that we need - we need to make more points, but he's the driver that we need," said Mattiacci this week.
"I think he knows what he can do better. He's a professional driver, he won a world championship with Ferrari; he's motivated, he knows his area of improvement.
"He sees Fernando ahead, he sees that it is tough and it's a tough moment, but we are all together in this."
Mattiacci concluded with a reassuring statement for the Finn:
"He has the utmost confidence and support from Ferrari," said the Scuderia boss.
34-year-old Raikkonen is currently on his longest run without a podium since his maiden season with the Sauber team in 2001, having completed 13 races since his last top-three finish. Should he fail to stand on the rostrum at the next five events he will break that record.