Sebastian Vettel expects Ferrari to be a threat for victory again in the Canadian Grand Prix given the Italian squad's practice pace.
Ferrari had a tough Monaco GP a fortnight ago, with Fernando Alonso only able to finish seventh.
But the Spaniard topped Friday practice in Montreal, and Red Bull driver Vettel reckons Ferrari looks rapid in both race trim and for single-lap speed.
He also suspects that Monaco winner Mercedes, which has taken the last three Formula 1 poles with Nico Rosberg, will be major qualifying threat.
"On one lap if you look at the timesheets, Mercedes was again very, very quick," said Vettel.
"Ferrari looks competitive on both long and short runs, so I think those will be the main two rivals.
"Never forget the Lotus because they can be a surprise in the race by going further [on tyres] than anyone else.
"It is difficult to say - you need to keep an eye all these teams I mentioned."
Vettel suspects Mercedes' qualifying superiority will continue.
"On the short run we have some room for improvement," he said. "Mercedes looks very, very quick again."
His team-mate Mark Webber said he was satisfied with the Red Bull both in the main dry running and in the wet conditions experienced at the start of practice one.
"We were pretty strong in both actually," he said.
"In the wet on the inters I felt comfortable straightaway. It is always tricky around here to get everything together in those conditions, if you are not comfortable you can bleed a lot of lap time but the car seemed good."