• Japanese driver Yamamoto partner Bruno Senna for Hispania
• ‘Karun Chandhok is still part of the Hispania Racing’

The Indian Formula One driver Karun Chandhok has been dropped for next week’s German grand prix, his Hispania team said today.

“After Sakon Yamamoto gave a very positive performance in Silverstone, the team has decided to give the Japanese driver another opportunity to drive the car alongside Bruno Senna,” they said in a statement.

“Karun Chandhok is still part of the Hispania Racing, HRT F1 Team family and is likely to be in the car at some later races this season.”

The 26-year-old Chandhok began his career in Formula One this season following three years in GP2. He started 10 races for Hispania, finishing in 14th place in Bahrain and Montreal.

Sport: Motor sport | guardian.co.uk

• Team keen to fix performance-enhancing diffuser before race
• Red Bull’s pace still seen as major threat in title fight

Lewis Hamilton and Jenson Button are to undergo a rigorous test programme on Friday ahead of the German grand prix.

McLaren were forced to abandon the debut outing of their performance-enhancing exhaust-blown diffuser during the final practice session before last week’s British grand prix at Silverstone. That resulted in the team’s mechanics working until 3am on Saturday, the day before the race, to restore the cars to the set-up used a fortnight earlier in Valencia.

That exhausting possibility looms again before Hockenheim now that the McLaren team principal, Martin Whitmarsh, has ordered a complete evaluation of both types of car during practice.

“The days since the British grand prix have been spent back at the McLaren Technology Centre,” said Whitmarsh. “We have industriously undertaken rig tests, dyno running and development in the wind tunnel to ensure the future deployment of the blown diffuser gives us a more accurate and beneficial read.

“Of course, that final validation will only come at the circuit, so we’re looking at undertaking a major test programme on Friday at Hockenheim. This will involve both drivers running back-to-back evaluations with the old and new floors.

“If these prove positive, we’ll then look at the deployment of the new floor for the remainder of the race weekend. But that’s a decision we’ll only make after a thorough analysis of the inherent risks and benefits.”

Whitmarsh will naturally be hoping McLaren have done their homework and get their sums right in the buildup to the race on 25 July. As Hamilton and Button have this week remarked, the team have punched above their weight of late in terms of results given Red Bull’s superiority when it comes to pace.

Whitmarsh knows, though, the upgrade needs to work sooner rather than later if his team are to retain their lead over Red Bull at the top of both championships.

“Silverstone showed we were in no mood to be complacent,” said Whitmarsh. “That was either in our aggressive push to put upgrades on the car, or our decision to remove them and put our faith in an older iteration of the car, despite a lack of running compared with our rivals.

“Ambition and decisiveness win world championships, and on both counts we got that blend right last weekend, which is pleasing. We’ve now come off an extremely successful run of recent races.

“But we’re nonetheless under no illusions. We know that we need to bring further performance to the car if we are to remain at the forefront of this championship battle.”

Sport: Motor sport | guardian.co.uk