Former Red Bull driver Webber is part of his younger countryman’s management team, along with his wife Ann Neal.
Together the couple helped to steer Piastri through the difficult period last year after he left the Alpine team in controversial circumstances.
The Contract Recognition Board subsequently confirmed that he was free to join McLaren.
“There's been a lot of advice from both Mark and Ann,” said Piastri. “I think to sum it up, I guess not underestimating the challenge of F1.
“It's obviously a big step up from what I've raced previously. And also it's a different dynamic racing in a sport, where this was my first year getting paid to drive race cars, which is pretty cool. So that's a different dynamic to what I'm used to.”
He added: "I think just being one of two drivers in a team of 700 or 800 people that we have here, it's a big responsibility. So I think that's a bit of a difference, and Mark and Andrea [Stella] and Zak [Brown] as well, I don't want to say a gentle reminder, but they reminded me of the responsibility that I have, and the impact that I can have on the motivation and the productivity of the team.
"Also being in a position to have a very key input into the design of the car. Obviously not building parts myself, but telling people what we need from the car, and ]the team] being able to make different parts in the car to address that, is something I'm looking forward to.”
Piastri also paid tribute to Webber and Neal for the support they’ve given him, especially last summer.
“Mark and Ann do a lot for me, I guess mostly behind the scenes, making sure that I really have to focus on the essentials, I guess, of F1.
"And I think this year especially I've been very grateful for their support and everything that they can do to make my life as easy as it can be.
“And throughout last year that was no different, guiding me through all of that, and doing all the background work as well. So they've been a massive help in my corner. And I'm really grateful to have them on my side.”
