Ricciardo was ruled out of the Dutch Grand Prix following Friday practice last weekend after breaking his hand following a crash.

The 34-year-old underwent surgery on his fractured metacarpal in Barcelona last Sunday.

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Liam Lawson deputised for Ricciardo in Zandvoort and Monza, and is expected to so for as long as the Australian is unable to race.

After back-to-back European races, F1 will have a week off before racing in Singapore.

One week after Singapore, F1 heads to Suzuka in Japan, and Horner is doubtful Ricciardo will be ready to drive in either of those two events.

“I think certainly Singapore, I don’t think there’s any chance he’ll be ready for then,” Horner said.

“It would be optimistic for Japan but his recovery is going well. He’s got mobility of the hand and is into rehabilitation now.

“We’ve seen with motorcyclists rushing comebacks they can sometimes do more damage. So we just want to make sure he’s fully fit before we get back in the car.”

“I should think he’s [Lawson] pretty keen to be in the car in Suzuka. We’ll just take it on a day-by-day basis and see how the recovery and nature takes its course.”