There are four official rookies - drivers who have raced in two grands prix or fewer - as well as two drivers who are getting set for their first full-time position in the sport, having previously been used as stand-ins.
That definition applies to Red Bull's Liam Lawson and Haas' Ollie Bearman, while the four rookies on the grid are Kimi Antonelli, Isack Hadjar, Gabriel Bortoleto and Jack Doohan.
Gabriel Bortoleto won the 2024 F2 championshipThere are a number of rookies entering F1 in 2025
F1's class of 2025
Hadjar and Bortoleto arguably have the highest stock coming into the 2025 season due to their F2 championship battle in 2024, although Antonelli and Bearman are the bigger names due to their links with Mercedes and Ferrari respectively.
Bortoleto claimed F2 championship success, beating Hadjar to the title by 22.5 points, although the title did come down to the final races of the season in Abu Dhabi.
Sunday's race though proved a baptism of fire for the rookie racers, with Hadjar spinning out of the race on the formation lap, while Jack Doohan crashed on the first lap. Bortoleto and Lawson would also spin off later in the afternoon in the highly slippery conditions, leaving just Antonelli and Bearman reaching the finish line.
The 20-year-old Bortoleto is the first Brazilian to race full-time in the sport since Felipe Massa in 2017, who retired having claimed 11 grand prix victories and 41 podiums.
Bortoleto's achievements in both F2 and F3 have not left 81-year-old Marko impressed, however, with the Red Bull advisor giving the Brazilian a rather harsh mark ahead of his grand prix debut.
"I would classify him as a ‘B’ driver," Marko told Servus TV. "He’s a very intelligent driver: he won the Formula 3 championship, but with only one win and he usually stays out of trouble.
"In Formula 2 he only managed two victories. He is a driver who brings the car home safely, has a good command of strategy and tyre management, but I don’t see that pure speed in him."
Isack Hadjar narrowly missed out on the F2 championship in 2024
That assessment was in stark contrast to what Marko thought of Red Bull junior driver Hadjar, who finished runner-up to Bortoleto in the 2024 F2 championship: "Hadjar lost the championship by only four or five points," Marko continued.
"Our data analysts calculated that he lost about 80 points due to technical failures and other problems.
"So he is very fast. I would say that if he continues to develop well and learn to control his emotions, he has A-level potential as well."
While handing out exam-style grades to drivers, Marko also suggested that Alpine star Doohan was a 'C'.