McLaren team principal Martin Whitmarsh had cause to congratulate Lewis Hamilton after witnessing his discipline following his smash in practice yesterday.

Hamilton was the main casualty of the wet conditions that prevailed over Hockenheim in the morning as he ripped off the front wing and left rear wheel after sliding into a tyre barrier.

The 25-year-old did not return to the track until 12 minutes from the end of the second session, covering 10 laps that creditably saw him clock the seventh fastest time.

Hamilton finished seven tenths of a second behind Fernando Alonso in his Ferrari, yet could have gone much quicker, only to spurn the opportunity as he preferred to focus on getting in as much running as possible rather than attempting to set a fast time.

"Losing track time was a little bit of a setback," said Whitmarsh.

"But I actually have to congratulate Lewis.

"Because he got out there late I was niggling the engineer, telling him Lewis should have a run, come back and put on the (softer) option tyre at the end.

"It was Lewis' discipline that said 'In the limited time I just want to do one run on the prime (harder) tyre because I know when I put the options on it will be quicker, so I dont need to prove it'.

"I spoke to Lewis after and congratulated him on his discipline because I would probably have tickled him into doing a late run on the option tyre."

It was a run that helped provide McLaren with the data they needed to determine their new performance-enhancing exhaust blown diffuser is good enough to remain on the car this weekend.

After Friday practice a fortnight ago ahead of the British Grand Prix a decision was taken to ditch it as it was not providing the team with the gains they had expected.

Whitmarsh, though, was satisfied they now have a design that does not cause issues and should be good enough to see them challenge the Red Bulls and Ferraris in today's qualifying.

"Based on the data we will be running it," confirmed Whitmarsh.

"The problem with yesterday is that with limited running, it is difficult for a driver to go out and say 'This is the way to go', so you have to rely on data.

"Given the data I saw we should have the confidence that this floor will do everything we expect it to, or most of what we expect it to."

Hamilton conceded afterwards he could not feel too much difference to his car in his limited running yesterday compared to practice at Silverstone.

But he knows they have the basis of a concept they can now work on and improve whilst it is on the car at races, and not just in the simulator, as had previously been the case.

"If I'm honest I've not noticed a huge difference. I've noticed something, but I don't feel like 'wow, this is huge!'" remarked Hamilton.

"For me it feels very similar to the way it did at Silverstone, so it's not bad. It feels like there is potential there."