Romain Grosjean to start Mexican GP from F1 pitlane

The Haas driver complained that "something is not going right" after qualifying 21st and slowest of those to set a time, lapping half-a-second off team-mate Esteban Gutierrez in Q1.

The change of floor is in breach of F1's parc ferme regulations because it is a different specification to the original one used in qualifying, meaning Grosjean must start from the pits.

"In qualifying, something just didn't work," said Grosjean yesterday.

"We have to move the aero balance all the time and that's not a good sign.

"We are investigating everything because something is just not quite right.

Team principal Gunther Steiner admitted that, on top of Grosjean's problems, Haas struggled more than most teams to get the tyres to work.

"Everybody struggled [with the tyres] but we struggled more than the other ones, otherwise we wouldn't be where we are so we just have to try to understand what is happening," said Steiner.

"It's always difficult when you start from these positions, but it could be a weird race because everybody dislikes these tyres and there are different strategies.

"So I hope it is an interesting race - maybe we can be good.

"I don't think we can get in the points, but we can learn more about why we are where we are."