Get ready for popcorn.
We have 3 contenders for the seat maybe 4, Lawson Colapinto and Tsunoda.
After the poor year from Perez with Redbull there are no chances for him to race another year.
According to him the most probable is Lawson.
Perez is predicted not to be able to maintain his seat in the next season's race because his performance does not show any improvement. He as the second driver did not show his function to help Max get his best performance, instead he only struggled in the middle of the board which is where RB does not want that. Replacing him next season is also a wise decision that can be taken by RB to improve their performance, and giving Lawson the opportunity for the seat could be the best option.
Even though Tsunoda has a good performance, we understand that he is not RB's "biological son", he is just a Honda consignment who wants there to be a Japanese person on the grid. And for Colapinto, giving him a seat as big as RB might put him under pressure, if he can't meet those expectations then it will be a new problem for RB, so it's still risky. The most reasonable one is Lawson.