Daniel Ricciardo is unlikely to return to the grid for the Singapore Grand Prix in two weeks’ time, says Red Bull team boss Christian Horner.
Reserve driver Liam Lawson has stepped in for Ricciardo at Alpha Tauri.
“Singapore, I don’t think there’s any chance he’ll be ready for then. It would be optimistic for Japan,” said Horner.
The race at the Marina Bay street circuit in Singapore on 17 September is followed by the Japanese Grand Prix at Suzuka a week later.
The Qatar Grand Prix in Doha takes place from 6-8 October.
Horner said Ricciardo’s rehabilitation from an operation to insert screws into the bone is “going well”and he “has mobility in his hand”.
Ricciardo made a surprise return to Formula 1 in July as a replacement for Dutchman Nyck de Vries, who was dropped after only 10 races with Alpha Tauri, Red Bull’s junior team.
The 34-year-old finished 13th in Hungary and 16th in Belgium before the summer break but crashed during second practice at the Dutch Grand Prix.
Horner warned that the eight-time race winner should not be pushed in his recovery.
He added: “We’ve seen with motorcyclists, rushing comebacks can sometimes do more damage and we just want to make sure he is fully fit before he’s back in the car.
“We just take it on a day-by-day basis and see how the recovery and nature takes its course.”