Mercedes will give Andrea Kimi Antonelli his Formula One practice debut at the Italian's home grand prix at Monza on Friday, team boss Toto Wolff said.
Antonelli, who celebrated his 18th birthday on Sunday, is expected to replace Lewis Hamilton in a Mercedes race seat when the seven-time world champion joins Ferrari next season.
"We're going to do FP1 [first practice] with Kimi in Monza, which is going to be a really emotional moment because we've followed him since he was 11 and a baby go-kart driver with a Mercedes kit and proud to be in the garage," Wolff told reporters at Sunday's Dutch Grand Prix at Zandvoort.
"Seeing him drive out on Friday in FP1 in Monza, in front of the tifosi, an Italian kid in a competitive car -- I think that will be something that everyone in Italy can be very proud of and I will take it from there."
Antonelli is competing in Formula Two but has also been testing privately with Mercedes in older F1 cars.
Technical director James Allison said in May that the youngster was very fast and showing "metronomic" pace in testing.
Red Bull's Max Verstappen, now a triple world champion, made his F1 debut at the age of 17 in 2015 and Mercedes believe Antonelli could be another generational talent.
Wolff ruled out the Italian racing this season after speculation he could be given a shot at Mercedes-powered Williams, who have already named a replacement for Logan Sargeant for 2025 and might drop the American before then.
Sargeant crashed heavily on Saturday and has yet to score a point this year.
"Between [Williams boss] James Vowles and myself, we have super transparent discussions and relationships," Wolff said of his former Mercedes colleague.
"And James was part of developing Kimi and finding Kimi.
"I think what's best for him [Antonelli] is to continue the program as we have designed it...and see how that goes, rather than disrupting our plan and giving him the opportunity in Williams. That's the decision that we have taken."
Wolff said Mercedes reserve driver Mick Schumacher, who is still hoping for a return to F1 after being dropped by Haas, deserved a run with Williams.
"I very much hope that Mick gets the chance, because we haven't seen the real Mick," Wolff said. "And if the opportunity would be in a Williams, it's something that we would be cheering for."