The Ferrari Driver Academy member, who currently lies sixth in the Formula 2 standings, is the latest in a line of Maranello proteges to get track time with Haas.
The team has been burned in FP1 before, with Antonio Giovinazzi crashing heavily as a rookie in Hungary in 2017, and again last year as a veteran at COTA.
With the cost cap biting and the US-owned team running its new package, an off for Bearman in FP1 would be a major setback for the team.
But Steiner has faith in the 18-year-old newcomer: "You're always a bit nervous.
“But, and hopefully I'm proven right tomorrow, he knows that the biggest mistake he can do is overdoing it.
“I explained to him you're always judged by the things you do badly, not the things that are good. Because if you do everything right, nobody will remember.
"But if you crash the car on your first outing in an F1 car in FP1, that will be on your resume for the rest of your life.
“If you ever make it into F1 because of that. You know how this business works, and I made him aware of that. I think he's smart enough to know that he doesn't go through anything stupid.”
Source: Autosport