MONTREAL -- There was awkward silence when Formula One drivers were asked on Thursday about the on-track antics of McLaren Mercedes' Sergio (Checo) Perez.
Aggressive driving by the 23-year-old Mexican has had veterans seething, especially Kimi Raikkonen, who suggested after the Monaco Grand Prix two weeks ago that some should "punch him in the face."
The six drivers assembled for the traditional race week news conference at the Canadian Grand Prix didn't want to touch questions about Perez, until finally Caterham's Giedo van der Garge offered: "If nobody comments, I will."
"I know Checo well. We were teammates in 2010. He's a real fighter. He's a guy who always wants to win," the Dutchman said. "How he raced in Monaco, sometimes he was doing well, sometimes he was going over. But it's a tough call."
Criticized for being too passive early in the season, Perez has gone on attack, leading to incidents with veterans like Fernando Alonso and even his own teammate Jenson Button.
In Monaco, an attempt to overtake on a chicane led to a bump with Raikkonen. The damage caused the Finnish driver to drop from fifth place to 10th and lose valuable championship points. Perez was later forced to retire with brake trouble.
Talk of Perez has even bumped the great tire debate from top billing this week.
The F1 governing body FIA has called on its international tribunal to rule on complaints that the Mercedes AGM team broke rules on in-season testing when it recently did 1,000 kilometres of tests in its 2013 car on a new compound of Pirelli tires.
The new tires are available for use by all teams in practice at the Canadian Grand Prix on Friday. They will get their first race workout June 30 at the British Grand Prix.
Mercedes could have used reserve drivers for the tests, but elected to have both F1 regulars Rosberg and Lewis Hamilton on the track.
"That was what the team decided," said Rosberg. "Also, for Pirelli, it's better if we're in the car because it's more representative."
He said reserve drivers wouldn't be able to maintain the same pace or "bring the Pirellis through the laps exactly as we do. So definitely for Pirelli it's an advantage to have us in the car, for sure."
The 11 teams will be on the track for practice Friday, with qualifying on Saturday and the race on Sunday.
Rosberg, who won in Monaco, will be gunning for a fourth straight pole position this season.
"Our car has been the quickest in qualifying for quite some time now,"he said. "We just have a very fast car.
"I'm confident I'll be quite far up the grid in qualifying here."