Williams head of vehicle performance Rob Smedley has admitted that he is "concerned" by how far his team finished behind Ferrari at the Malaysian Grand Prix.

The Oxfordshire-based outfit, who finished ahead of Ferrari in the 2014 constructors' championship, languished more than a minute behind race winner Sebastian Vettel.

According to Smedley, Williams need to work on the development of their car if they are to challenge the Scuderia over the course of the season.

"Yeah, of course I'm concerned," he is quoted by F1i as saying. "To be 60 seconds down at the end of the race, absolutely it's a concern. It would be remiss of me to say I wasn't concerned about that.

"But there's certain bits of it, like the fact that Sebastian could do one less stop than us has certainly helped in that minute, so that's where we need to start concentrating. At the same time we need to develop the car package from front to back, you need to keep pushing on with that.

"It's a concern – if anyone is in front it's a concern, no matter what colour their car is. We just have to keep pushing on and make sure we're developing at a faster rate than them. If we do that, we close a gap, it's that simple."

Valtteri Bottas finished fourth in the race in Sepang, while teammate Felipe Massa came in three seconds further back in fifth.