Di Resta replaces Massa at Hungarian GP

Massa felt sick and dizzy at the end of Friday's running at the Hungaroring and, after examination at the track's medical centre, he was transferred to hospital in Budapest for further checks. No major issue was discovered.

Although he felt better on Saturday morning and was given the all-clear to resume driving in final free practice, he was forced to cut short his running after suffering a relapse.

Amid concerns about Massa's fitness for what is usually a tough physical challenge in the Hungarian race, a decision was taken by Williams to substitute the Brazilian.

Williams reserve driver di Resta, who had been put on standby overnight, has been given the nod to take over the car for qualifying. He will race with car number 40.

In a statement, the Grove-based team said that it was Massa's call to sit out the rest of the weekend, adding: "Williams supports Felipe's decision and the team will work with him to ensure he makes a full recovery, with a view to return to the race track for the Belgian Grand Prix."

Without having driven in any of the practice sessions held so far this weekend, di Resta will need to get within 107 percent of the fastest time to be guaranteed a place on the starting grid.

It will be di Resta's first F1 outing since his final race for Force India at the 2013 Brazilian Grand Prix.

Since leaving grand prix racing, the Scotsman returned to the Mercedes DTM outfit, which had taken him to the series title back in 2010.

He's won two races since his DTM comeback, the more recent of the two wins coming at the Hungaroring.