TOTO WOLFF, the Mercedes director, has made it clear that changing his driver line-up represents a worst-case scenario which should never happen.

Wolff has warned feuding drivers Lewis Hamilton and Nico Rosberg if they continue to fall out of line then the team would consider axing either man. In the wake of the incident during the Belgian Grand Prix a fortnight ago when Rosberg collided with Hamilton, an uneasy truce exists.

Hamilton suffered a puncture to his left-rear tyre on the second lap at Spa after being hit by the front wing of Rosberg's car, ultimately forcing him to retire late on.

It resulted in Rosberg apologising and being fined a six-figure sum, but also extending his lead in the drivers' championship to 29 points over Hamilton after finishing as runner-up at Spa. The incident was the latest in a long line of improprieties perpetrated by both men over the course of the campaign.

It remains to be seen whether they can keep it clean over the final seven races, but Wolff has made it clear any further indiscretions could have long-term repercussions.

"We don't want this to happen ever again, and the consequences are very easy," said Wolff. "If we are not able to manage the two of them following the Mercedes-Benz racing spirit, then we need to admit that and take decisions and take consequences of having a different line-up probably."

Clarifying his remarks later, Wolff made clear neither man is at present in danger of losing his drive as he believes he and the team will find a way to manage the scenario. "At this stage we are very happy with the line-up, our two drivers, we have always said that," said Wolff said.

"We trust them, we had a very good, clear discussion with the two of them, that what happened in Spa shouldn't happen. As for my comments, they were about what would happen if we could not get on top of things, which is a worst-case vision. I don't think we'll get that far."

Normal service resumed in practice, at least, as Rosberg and Hamilton finished one-two come the culmination of practice yesterday.

After McLaren's Jenson Button had surprisingly split the pair in the opening 90-minute session around Monza - with Hamilton comfortably quickest - come the second run, Rosberg held sway over his team-mate. For over an hour, though, a frustrated Hamilton could only watch as his mechanics tended to his car which was plagued by an electrical issue.

He managed to complete 16 laps compared to Rosberg's 41, and might have finished top of the timesheet but for traffic when he did finally take to the track with 25 minutes remaining.