Conclusion
Recently Perez and Sainz have emerged as strong candidates to replace Raikkonen next year, but a major barrier to their signing is the fact that they are already under contract with their respective teams and it will take a lot of money to sign them up for the team.
Furthermore, drivers like Bottas and Rosberg seem to be available for next year as both their contracts are up for renewal at the end of this season.
It appears that Rosberg is most likely to stay with Mercedes, as the team still remain highly dominant, and probably the best position to give the German with a car to challenge for the championship. On the other hand, situation concerning Bottas seems more interesting.
Williams have recently slipped down in the grid order and Bottas having been with the squad for the past four years, will definitely be looking for better options for next year.
Given the fact that Ferrari had already been interested in the Finn last year, if Ferrari do indeed sign Bottas, then it should come as a no surprise. Thus, looking at the all the possible scenarios, in my view currently, Bottas seems to be in the best position to sign up for Ferrari next year.
With Ferrari having a tradition of revealing big announcements at the Italian Grand Prix, the same trend should be followed this time around too. But till then, we can only speculate and hope that the most deserving candidate gets the nod to join Ferrari next season.