McLaren team principal Ron Dennis believes Fernando Alonso is still the fastest driver on the Formula One grid.
Two-time world champion Alonso has struggled since switching Ferrari for McLaren in 2015, finishing among the points just three times out of 21 starts.
Former F1 driver-turned-pundit Johnny Herbert previously suggested Alonso should retire from the sport, but Dennis insisted the Spaniard is still at the top of his game despite constant poor results.
"I recently read an article in which a former driver said it was time for Fernando to retire," Dennis told F1 Racing.
"But look at him. In my opinion, which I think is well qualified, he is still the fastest.
"The best Formula One drivers, besides possessing the highest level of personal ambition, are also able to generate great loyalty among the engineers and the rest of the team.
"They are a rare breed, and I have to say that in the past Fernando was extraordinary in this regard."
Alonso is seventh in the drivers' standings, seven points ahead of team-mate Jenson Button despite missing the Bahrain Grand Prix due to injury.