Mercedes is close to reintroducing the underbody update that was not carried out last weekend in Belgium as soon as the Formula 1 season resumes with the Dutch Grand Prix.

The German brand’s relentless drive for development continued in the last round before the summer break, when the W15 was fitted with a modified underbody in training.

However, a disastrous performance in the first two hours of practice and the expected rain later in the weekend prompted Mercedes to revert to the previous specification.

Both Aston Martin and Ferrari and RB have had to contend with extensive update packages this season, which have had unintended consequences at certain stages.

However, Mercedes boss Toto Wolff denied that the team had suffered a setback, saying the problems from earlier in the weekend were due to the car’s mechanical setup.

“I think we made a drastic change to restore some of the performance, but we believe it was not the underbody,” Wolff said of Mercedes’ plans for the part.

“It will be quite interesting when we try everything on the car at Zandvoort and correlate it and see what it does.

“Then we can be sure that it is the mechanical part that we suspected, or that there are some interactions both aerodynamic and mechanical that did not work.”

This change proved to be a blessing, as George Russell, who took the lead in a Mercedes one-two after one stop, was disqualified because his car was 1.5 kilograms too light.

Andrew Shovlin, Mercedes’ Trackside Engineering Director, explained that the similarity of the track characteristics of Spa and Silverstone was also the reason for the team’s decision.

“The reason we removed them and essentially put the car back to Silverstone specification on Friday was because we had a good race at Silverstone,” he said.

“The Spa and Silverstone circuits do not differ dramatically in terms of cornering speeds.”

“We had obviously caused problems somewhere. We think that was largely due to the way we drove the car at Spa and not the updates themselves.

“This obviously caused us to have some bounce in the high-speed corners and caused some balance issues.”

“After switching to this Silverstone car, everything was back to normal.

“We’ve had time to look at the data to understand exactly what we’ve been doing. And knowing that, we’re pretty confident that we’ll reintroduce it at Zandvoort.”

But although Mercedes has won three races in four, Wolff pointed out that there is no guarantee that the upward trend will continue after the season restarts.

“I think we have to keep both feet on the ground,” warned the Austrian.

“When it comes to performance fluctuations, you can definitely see a positive trend on our side. For some other teams, you can see a negative trend.

“But I don’t think we should really prejudge how the second half of the season will go. I think it’s a tough battle and there are four teams giving it their all.

“I think we can be cautiously optimistic. But we have to prove it. There are still 10 races to go.”