ESPNF1:
"I'll sit down with him and let's go through the weekend. Obviously it's always the same story - especially in Monaco - he had the pace. We could see it, so it's even more frustrating because of that. Thursday's accident didn't help but it happened. The rest of the story went worse on Saturday morning.
"Building his frustration was again Ricciardo which didn't allow him to complete the Q2 like he should have done and ended up 13th on the grid just to finish his frustration. So I think we just need to cool him down and have a proper discussion when we're back in the factory."
However, Boullier insisted he felt the weekend was just a one-off and not Grosjean slipping back in to the bad habits of 2012.
"It's not a worry, he did a great job over the winter and fixed all the problems he had last year. So it's just some frustration sometimes when he knows he can be fast and he just needs to build himself up saying he is fast and he can deliver some big results. He did it in Bahrain, he was on the way to doing it in Barcelona, so it's just not losing the momentum and making sure he's back on track with the real expectation."
Asked if he had considered substituting reserve driver Davide Valsecchi in to Grosjean's seat for a race, Boullier replied:
"Not yet." There's light at the end of the tunnel
