After making a disappointing start to the season, Williams driver Felipe Massa has admitted that they need to step up their game as they are falling behind their rivals.
Despite scoring points in the opening three race, Williams duo Massa and Valterri Bottas were expected to be challenging the top-end of the grid with their Mercedes powered engine.
However, the Brazilian said that they are lacking pace compared to Red Bull, Ferrari and Mercedes, who remain the favourites to win the championship double.
“Three teams are in good shape, better than us,” the former Ferrari man told Brazil’s Globo.
“We can get a little closer – depending on the track – to Red Bull in qualifying. But we know that in the race they have a much stronger car.
“I finished in the best position I could.”
The former Ferrari driver, who is a longshot with Paddy Power for the Russian GP podium, has urged Williams to resolve their issues.
“We really need to understand where the other cars are better than ours.
“We know it will not be easy, but we will continue to fight and to work.”