Mercedes are poised to sign Kimi Antonelli to replace Lewis Hamilton for 2025. Carlos Sainz’s move to Williams removes Antonelli’s only real rival for the seat. Toto Wolff has also spent much of the season courting reigning world champion Max Verstappen. But it appears the Dutchman may not have a route of his contract at present. Helmut Marko recently signed a key contract extension at Red Bull, closing off a potential exit door. Previously, Verstappen was able to depart if Marko left his post. But it seems the 26-year-old will now have to wait 12 months before he has the opportunity to change…