Red Bull's Mark Webber admitted he was surprised to learn that Mercedes had carried out a secret tire test with Pirelli after the Spanish Grand Prix. But he does not believe it was a major factor in Nico Rosberg's win for the squad in Monaco.
Mercedes took its first Formula 1 victory of 2013 just hours after it was revealed that it had covered 1000 kilometers over three days of tire work at Barcelona last week. Red Bull and Ferrari subsequently lodged a formal protest, as Pirelli insisted the test had mostly been on 2014 preparations and was permitted within the rules.
Webber finished third in Monaco, behind Rosberg and the sister Red Bull of Sebastian Vettel.
"I think we were probably a bit surprised it happened," said Webber of the test. "I don't think it probably had a huge bearing on today's results, That car would always perform pretty well around here, to be fair.
"But you can't unlearn what went on at the test. So we need to see how it came about and what the rules are to see why Mercedes thought it would be OK.
"Time will tell, but it didn't affect today's result."
Webber has been a consistent critic of the high-degradation Pirelli tires and their impact on F1, and he said Monaco had been more of the same.
"We were basically saving the tires and making the one-stop work," he said. "All the drivers were having to nurse their cars very aggressively.
"Generally we were just driving around, protecting tires and waiting for the checkered flag."