Nico Rosberg says Friday is always tricky to realise his rivals true pace and feels Red Bull has been turning down its engine in the second free practice which is reflected in the timesheet.
The current F1 championship points leader has ended FP2 third fastest overall behind leader Lewis Hamilton and Ferrari's Sebastian Vettel and feels there are still areas of his set-up he wants to address before being settled for the race.
The German driver also noted that despite Max Verstappen and Daniel Ricciardo being fourth and fifth respectively for Red Bull he is convinced the one-second deficit it trails to Hamilton's top time is because it back out of turning up the full power on its new Renault engine configuration.
“The long run is looking good, our car is looking good but Ferrari is looking close today,” Rosberg said. “It is always so difficult on Friday you never know what fuel levels they are running, how much engine power they are using.
“At Red Bull they had their engine turned down completely which didn't show anything so let's see.”
Rosberg leads the F1 world championship by 24 points from Mercedes team-mate Hamilton and is keen to return to the top step of the rostrum in Canada after two underwhelming results in Spain and Monaco.