Michael Schumacher will be behind a F1 wheel for the first time since '06.

THE ASSOCIATED PRESS

VALENCIA, Spain -- Michael Schumacher marked his return to Formula One by setting the third-fastest lap time during a testing session on Monday driving for his new Mercedes GP team.

The former Brawn GP team rolled out its W01 car at Valencia's Cheste Circuit, with Nico Rosberg kicking off three days of testing by being third quickest before the lunch break.

But seven-time world champion Schumacher, who is back after three years out of the sport, needed 17 laps in the afternoon to beat his teammate's time before eventually clocking a best lap of one minute 12.947 seconds. That was less than four-tenths of a second off the pace set by his former Ferrari teammate Felipe Massa.

"It was a perfect rollout for the new car today. I felt totally comfortable and really had a feeling that everything was very natural," Schumacher said. "It felt just like at the very beginning of my career in 1991 when on the first lap, I thought 'wow that was really fast' and then on the second lap, I was just extremely excited."

The 41-year-old Schumacher, who was driving for the first time since the 2006 Brazilian Grand Prix, said his neck felt "very good" after it had kept him from returning last summer to replace the injured Massa.

"It would have been more of a surprise to me if he hadn't been where he was today," team principal Ross Brawn said. "It was just like old days."

Schumacher said he felt like "a kid with this toy in his hands."

"I think we have done a very good job," the German, who holds most of the sport's record, said. "The guys did a superb job with their control checks today to make the car reliable."

Seeing Massa and the red Ferrari on the track was a little surreal, however.

"I suddenly see my old car on the track -- it's a strange sensation," said Schumacher, who was given the green light to return after recovering from the neck and back injuries sustained in a motor bike accident last year. "But it's good to see (Massa) on the track. I enjoy to see my friends."

Fellow German driver Rosberg also gave a positive impression of the car, which last year helped Jenson Button to the championship and Brawn GP to the constructors' title.

"There are so many new circumstances that I cannot feel is it a winner or is it not a winner. It generally felt very good," Rosberg said, putting emphasis on how the ban on refuelling will shape the new season. "In recent years you would have a better impression, but now with the fuel level you really don't know what other people are running either."

Rosberg, who had the day's fourth-fastest lap and was just under half a second behind Massa, said he felt "at home" with his new team after four years at Williams.

Brawn said that Rosberg didn't have the best day since his seat was not properly fitted, but he remained encouraged by the defending champion's start.

"There's nothing fundamentally wrong with the car, the drivers are reasonably happy with the balance ... nothing suggests there is anything strange but it's far too early to judge," Brawn said. "It was a starting day, a day to get things moving."

Aside from the new silver-and-green livery, the most notable change to Mercedes' first F1 car in more than 50 years was the nose section, which features its own take on a configuration begun by Red Bull last season.

Once both drivers have adapted to the car, they will also have to work together, with Rosberg already motivated by Schumacher's arrival.

"It has given me a little bit extra motivation, I must say, just that little touch extra to have him there," Rosberg said. "I get on well with him for now and he respects me also and I respect him, so it's good. I think we can get on very well and be very good teammates."