Since the first stage of an intense programme of upgrades appeared in Austria Lando Norris has secured four second places, while his team-mate Oscar Piastri earned his first podium with third place in Japan last weekend.
While the surge in form has been eye-catching Vasseur believes that McLaren underperformed in races earlier in the season while already showing flashes of good pace over one lap, notably in Spain, where Norris qualified third.
"I'm not sure if we have exactly the same reading of the season,” said Vasseur when asked by Motorsport.com about the MCL60’s pace.
“I think that they had a big issue at the beginning, and then they recovered pretty quickly because, even in Barcelona, they were on the second row.
“I think it was Max [Verstappen], Carlos [Sainz] and then Lando and Lewis [Hamilton] on the second row, they were already competitive.
“And this kind of track is probably suited more with their car than us. But for sure it's not just a matter of pure potential, it's a matter of driveability also.
“Each time you will do a step forward you will also help the driver to do a step forward, and this can be a kind of snowball effect. Still, a small step compared to Red Bull!"
Vasseur agreed that Ferrari’s race at Suzuka was further proof that the Maranello team had got on top of the tyre management issues that hampered its drivers earlier in the year.
Charles Leclerc finished fourth, albeit some way behind the McLarens, while Sainz was sixth, having chased Hamilton’s Mercedes across the line.
"I think it's a step forward compared to the beginning of the season,” said Vasseur of the tyre usage.
“But on the other hand, we were probably a bit too conservative, and I think it was true for everybody on the grid that we were more scared than the reality. It was under control in the race. And we think we did a good step forward on this one.
"It’s sure if you have a look on the first couple of races of the season, the degradation or the tyre management, were not always our biggest skill, let’s say.
"And coming to Suzuka with this track temp we were a bit at risk. But at the end of the day, I think we did a good job on this side.
“The race was under control, the strategy was well managed. We did well. A clear step forward compared to the first part of the season."
Vasseur insisted that the team made good calls with Sainz, notably leaving him out for a late second stop in order to give him fresher tyres with which to attack Mercedes duo George Russell and Hamilton.
"I think the first stop was really on the edge to keep the two cars in front or to put Lewis in front of the two cars,” he said. “And it was a matter of tenths probably, and I think it was the right call from the team.
“The second one was a bit more strategic. And I think the call came also from Carlos, but we agreed that we have to extend to try to have a tyre advantage in the last couple of laps because if you copy Lewis, you are behind him, and without a big delta you stay behind him."
