Ahead of his F1 debut, Franco Colapinto admits to being surprised to being called on by Williams to replace Logan Sargeant for the remainder of the season.

While the American was expected to be dropped over the summer break, much like Sergio Perez at Red Bull, Williams opted to persist with the American in his sophomore season. However, he fully blotted his copybook at Zandvoort, crashing heavily in final practice and consequently being unable to take part in qualifying.

Days later, Williams announced that it was game over for the youngster as it called on Argentine Colapinto, even though both Liam Lawson and Mick Schumacher had been linked with the seat.

While he took part in last year's end-of-season young driver test, it was at Silverstone, ahead of the summer break, that Colapinto made his F1 debut, replacing Sargeant in the opening practice session.

Speaking at Monza, the youngster admitted his surprise at getting the call.

"For you to imagine, on Monday I was in the Formula 2 team with MP preparing the race with my team for Monza," he told reporters.

"So you can imagine how late it was," he continued. "I don't know when they were thinking about, but it's an opportunity that I've been always ready for and that I've been waiting for so long. Since I was a young kid, I was always dreaming of this coming true and happening. And today to have the opportunity to be here speaking to all of you, it's a pleasure.

"I am just extremely grateful with Williams for the opportunity," he added. "It came very late, of course, but I'm always ready. I was not expecting it, to be honest. But I cannot explain you how happy I am to be here with Williams. They have been very supportive and the opportunity that they have given me is insane.

"I'm always ready," he said of the decision to move up to the F1 race seat at Williams. "I've been the driver in the background for them for a while. Of course, I did the Free Practice One in Silverstone. I did a good job there. They were very happy about the performance and I think I was probably in their mind from before.

"Of course, something maybe I was not waiting. I was fully focused on my Formula 2 season. It was my job before and I was trying to do the best possible. I had four races left. I was preparing with the team as best as possible and this was the game. Of course, I'm very sad to not continue with them. They have been my family for so many years, since 2020 that we started racing together and I continue doing step by step, championship by championship.

"But today I have to leave them. However, you cannot choose when you get to Formula 1. I came in this time, in this race. This is a very special weekend here in Monza. So I am super happy, to be honest. I'm very grateful with this working chance."

Asked how much preparation he has had for his debut, he said: "Well, not a lot. You can imagine I've got a lot of preparation to race in F2. I can go there and do a good job. We've done in a very, very short time a lot of things. It's only Thursday today and in the very little amount of time and hours that we had, we worked very well.

"I prepared a seat. I prepared the simulator very, very well," he added. "The race engineer, the performance engineer, they are giving me all their information, all their tips and details to be quick as soon as possible. And to make that learning process a bit quicker.

"So yeah, luckily I think I am privileged that I was able to be in the simulator for so long in the past, even though I was racing only in Formula 2. Because at the end it prepared me a little bit more to Formula 1, to go through all those processes. You've got so, so many things to do in the car.

"I think to be doing laps and laps and laps there, it helped me a little bit to be a bit more comfortable today. I sit in the car and I know the wheel and many things that are sometimes a bit difficult.

"I think especially with quite a few races to go, it's just starting a bit more relaxed and trying to go step by step. So yeah, I'm very happy for this chance and to be here.

"My main focus is focussing on myself, trying to do the best job I can," he said when asked if he has been given set targets. "The team has very clear targets, which we are focussing on. So I am focussing on that too and trying to learn as quick as possible.

"As I said before, they are very supportive. Everyone has been giving me a very warm welcome and I am happy to be there with Williams."