Rumours that Fernando Alonso may test the 2019 car during winter testing have not been confirmed by the team.
McLaren is hopeful that their 2019 car will represent a departure from the poor period they have undergone since the beginning of the hybrid era.
Speaking ahead of winter testing, McLaren sporting director Gil de Ferran praised the two-time world champion's ability but refused to confirm if the Spaniard would be testing for the team in 2019.
"We don't know yet, we'll see. Obviously, to know how competitive the car is going to be with the new rules, we have to wait and see it in the Barcelona tests," he said.
"I have always said that for me Fernando is one of the best drivers in history," he added.
De Ferran, who it was announced earlier in the year would have a role in the new electric 4x4 series, Extreme E, added that his new role wouldn't hamper his McLaren commitments in Formula One,
"I will not have a day to day role in Extreme E, but obviously I would love to see that it is successful," he said.
"I support Alejandro (Agag) and his team with the best of my abilities."