McLaren is hopeful Lando Norris will be fit for this weekend's Monaco Grand Prix but will make a decision on a potential replacement "at short notice".
The British driver was unwell across the Spanish Grand Prix weekend and after fighting his way to eighth in the race, was diagnosed with tonsilitis by medical staff.
With the short turnaround between Spain and Monaco, Norris faces a race against time to ensure his fitness for the jewel in F1's crown around the streets of the Principality, where he picked up a podium for McLaren last year.
On whether Norris was a doubt for the race, team principal Andreas Seidl said: “First of all, I think with the medical support we are having and with having the possibility now to rest for four days, I am hopeful that Lando will be fit."
McLaren is known to have a pool of drivers to choose from should Norris or Daniel Ricciardo miss a race, with Mercedes drivers Nyck de Vries and Stoffel Vandoorne available, as well as former F1 driver Paul di Resta and Alpine reserve Oscar Piastri.
“But as you know, we have different options in terms of reserve drivers prepared which we would pull in case of an emergency," added Seidl.
“But again, we are quite hopeful that Lando will be okay again by next Friday latest.”
Pushed as to whether Piastri, who tested for Alpine in Qatar ahead of the Spanish event, was high on the list, Seidl insisted a decision would be made closer to the weekend.
“In terms of the reserve driver, that is something we would work out on short notice, which of the options we would pull," he explained.
"It depends also on the availability. Not all of the guys are always available because of other commitments for other racing series.”