By Alan Baldwin
(Reuters) - Mexican Sergio Perez was fastest for Red Bull on the final morning of Formula One's pre-season testing in Bahrain on Sunday while champions Mercedes sounded positive after previous setbacks.
Perez, who will hand over to Dutch team mate Max Verstappen for the afternoon stint, lapped the Sakhir circuit with a best time of one minute 30.187 seconds on soft tyres.
The lap was the fastest of testing so far, although Perez did fewer than others with only 47 completed. The later four-hour session should see the cars go quicker in the cooler conditions.
Ferrari (NYSE:RACE)'s Charles Leclerc was second on the timesheets, but with 80 laps completed, and McLaren's Lando Norris was third with 56 laps.
Valtteri Bottas was at the wheel for Mercedes, with seven- times world champion Lewis Hamilton due to take over after lunch.
Although only seventh fastest, the Finn did the second most laps with 84 and said the team had made up ground after a difficult opening Friday when he had managed only six laps due to a gearbox problem.
"I feel like we made a decent recovery," Bottas told reporters.
"I can't say that we fully achieved the mileage we wanted to get in the three days but actually we're not that far off. Yesterday I feel like we made 95% the most out of it and today I would say 100%.
"We had a really solid day today with a good amount of laps and quality laps...considering what happened day one, how day two and three went I'm pleased with that but now it's time to turn that data into performance somehow."
George Russell finally got on track for Williams (NYSE:WMB) after sitting out the first two days while Israeli development driver Roy Nissany and Canadian Nicholas Latifi put laps on the car.
Alfa Romeo's Kimi Raikkonen did the most laps of all, completing 91.
The season starts at the same circuit on March 28.