Lotus backs Grosjean to rebound from difficult Monaco GP

Grosjean endured a troubled weekend in Monaco, where he showed good flashes of speed but crashed on each day of action.

His race-day collision with Daniel Ricciardo earned him a 10-place grid penalty for the next race in Canada.

Although Grosjean has not had a smooth start to the campaign, Boullier believes that it is up to his team to help the Frenchman rediscover his top form.

"We want him to keep the pace and make sure that he is back in control like he was at the beginning of the season," he said.

"We need to sit with him and go through the weekend. He had the pace and we saw all weekend he could do it.

"And it is even more frustrating because of that.

"On Thursday he obviously didn't help himself, but it happens. And then the rest of the story went worse.

"We need to cool him down and have a proper discussion when back in the factory."

When asked if Grosjean's ongoing problems were a concern, Boullier said: "No, not a worry. He did a great job over the winter to fix all the problems he had last year.

"But there is some frustration sometimes when he knows he can be fast.

"He can deliver some good results. He did it in Bahrain and he was on his way to do it in Barcelona, so it is just about not losing momentum and that he gets back on track."

Grosjean's issues have already prompted speculation he could be rested by the team to get himself back in shape.

Pushed about if there was a chance reserve driver Davide Valsecchi could be given a try out, Boullier said: "Not yet..."