Carlos Sainz is back in contention to join Mercedes. The prospect of an inadvertent driver ‘swap’ with Ferrari is still alive. It emerged during the British Grand Prix weekend that Mercedes are once again giving serious consideration to signing Sainz. They have concerns over whether academy driver Kimi Antonelli is ready. Toto Wolff says there are still things Antonelli ‘needs to learn’, though he did score his first F2 victory in the Silverstone Sprint Race. Mercedes have understandably given him time to prove himself as they decide whether to replace a seven-time world champion in Lewis Hami…