In recent weeks, the Frenchman looked set to lose his seat at Haas amid a season of notable mistakes.
But circumstances have suddenly swung back in his favour.
It is believed Ferrari tried to place Charles Leclerc at Haas for 2019, but team owner Gene Haas did not agree with that move.
Haas appears happy with Kevin Magnussen, and it is now believed the American team might also want to keep Grosjean. At Monza, he finished a solid sixth prior to being disqualified over an illegal floor.
“I was not very proud of the start of the season, but I knew I would find the key. And now I’m back to normal,” the 32-year-old told Ekstra Bladet newspaper.
When told about Grosjean’s ‘key’ comment, team boss Gunther Steiner said: “I hope he doesn’t lose it again! I’d better ask him where he puts it in case he loses it again. Maybe we need a red string on it.
“Joking aside, Romain has been racing for a long time and is very experienced. He knows how to handle himself. So if he says that, I hope that it works.
“This is how Romain goes normally. We just need to make sure he does it all of the time and avoids all these fluctuations. There are limits to how many of those you can do.
“But I think he is doing fine right now,” Steiner added.