McLaren Formula 1 driver Fernando Alonso says it is "amazing" a Honda engine failure stopped his team-mate Stoffel Vandoorne from even starting the Bahrain Grand Prix.
Vandoorne was withdrawn after Honda found a problem with his engine on the reconnaissance lap to the grid.
Honda has not revealed the cause but initially believed it is the same MGU-H problem that caused multiple failures across practice and qualifying.
When asked for his thoughts on Vandoorne's failure to take the start, Alonso replied: "Amazing".
He added: "Amazing because we've been working very hard, and Stoffel is working very hard.
"This weekend he had so much bad luck with power unit changes, and then not even to participate...
"You can be fast, slow, at times, in different races, in different circumstances.
"When you cannot even start the race, it's amazing."
Alonso retired for the third consecutive grand prix, having run just outside of the points for the duration of the Sakhir race, as McLaren's troubled start to the 2017 season continued.
He complained to his team during the race he had "never raced with less power in my life" and later described Honda's performance deficit as "impressive".
Alonso said the Bahrain event featured "too many reliability problems".
"And even for Stoffel not even able to start the race, it's an unacceptable situation," he added.
"We'll see what we can do from now to Russia, because we need to really do better than here."
VANDOORNE 'DOESN'T WISH SITUATION ON ANYONE'
F1 rookie Vandoorne attempted to play down any personal frustration with Honda's ongoing problems after the race.
When asked if his patience was running thin, the Belgian admitted: "It's definitely not an ideal situation.
"I don't wish anyone to be in it like this. But we knew at the start of the season that it was going to be a tough time.
"This weekend really showed what it's like. It's a shame to not start the race.
"It's frustrating when you do all the preparation work - us drivers train a lot, keep fit, to be able to go racing - and then not being able to start is a bit frustrating."