Rosberg bemoans Indy 'disaster'

The Williams driver had made the most of a one-stop strategy to move from 14th on the grid to sixth position with just five laps remaining.

But then the German was hit by an engine failure that forced him into retirement, leaving him very frustrated.

"Well, it was a disaster," said Rosberg. "The strategy was good. We had a good choice of tyre and everything. The race was going well. I was sixth. It would have been a great result for us again.

"Then the engine blows up. I'm not sure if it was the engine. But something blew up in the back. But with six laps to go, so that was pretty bad.

"I was feeling pretty good. I was pretty comfortable. It wasn't easy, but being comfortable, I was able to put down some good lap times toward the end of the first stint. I was moving up places all the time. I was really looking forward to a good finish."