Ross Brawn believes McLaren must have "paused for thought" after seeing former engine supplier Honda take its first victory in Formula 1 since returning to the sport.
McLaren and Honda linked up in 2015 with the aim of challenging the frontrunning teams for wins and titles, but it was a partnership fraught with disappointment as both parties failed to deliver leading to a divorce at the end of the 2017 season.
It was costly for McLaren as not only did Honda supply its engines for free, it also contributed tens of millions to the team's budget, and not only that, but McLaren had to pay Honda to break its contract and link up with Renault for 2018.
Honda moved over to Toro Rosso and then a year later added Red Bull and just last weekend, less than a year into their partnership, secured their first victory thanks to Max Verstappen at the Austrian Grand Prix.
Although Brawn hailed McLaren's current form with partner Renault, he questioned how the team might have felt after seeing Honda win a race before they have since splitting.
"After years of suffering the team is back on track and has put together a string of results that makes it favourite for the fourth place, which is the most that the ‘normal’ teams can aspire to this year," Brawn said.
"Certainly the fact that on Sunday Honda won as an engine manufacturer for the first time in almost 13 years, might have given them pause for thought, but they can only be pleased about being 20 points ahead of Renault, their own engine supplier’s official team."
Brawn also commended their driver pairing of Carlos Sainz and Lando Norris, and hailed the young British driver as the best of the rookies.
"The team can be very pleased with its driver pairing, with Lando Norris definitely the most impressive of the three rookies in the field, with four points finishes and several strong showings in qualifying to his name.
"Carlos Sainz has also proven his worth and last Sunday’s race was probably his best, especially in the light of the fact that, in the race of no retirements, he started from the back row and finished eighth.
"McLaren has scored 52 points in this year’s nine races, which is only ten fewer than it managed in all of 2018 and 22 more than it scored in 2017, which is further evidence of the progress made."