Seven-time MotoGP champion Valentino Rossi's patience looks to be running out, after his debut on the 'all new' Ducati Desmosedici GP12 turned into one of his worst weekends in the premier-class.

Rossi rode from ninth on the grid to seventh during a tough Ducati debut at the same Losail circuit in 2011.

Fast forward a year and, despite massive technical changes to the motorcycle following a season of racing input from the Italian rider and his mechanics, the situation was even worse.

Twelfth and ahead of only the Superbike-powered privateers in qualifying, Rossi spent the early part of Sunday's race in tenth place, until a rough pass by satellite Ducati rider Hector Barbera bumped him back to twelfth.

Retirement for Karel Abraham and a pass on an off-the-pace Ben Spies returned The Doctor to tenth by the chequered flag.

Almost 34 seconds behind race winner Jorge Lorenzo - over double the victory difference of last season - Rossi could have been in contention for the sixth place achieved by team-mate Nicky Hayden without the time lost during the Barbera incident.

But that was of little consolation.

"Unfortunately, I lost a lot of time in the beginning because when I had new tyres with good grip, the rear pushed a lot, making it very difficult under braking," explained Rossi.

"Then Barbera pushed me off the track and I lost five or six seconds. Otherwise, I could have stayed with that group.

"As the tyre became used and began to slide, I started to ride a bit better and to do better times, to the point that I matched my best time on the last lap. By that point though, it didn't count for much."

Rossi, a 79 time premier-class race winner, has celebrated only a single podium since leaving Yamaha at the end of 2010. And after such a demoralising start to 2012, it seems Rossi's patience is starting to wear thin.

GPone.com quotes Rossi as saying: "Ducati didn't follow the direction that I indicated, but I'm not an engineer and I can't solve every problem.

"...The problems with the bike haven't changed, and neither have my requests. It's unrideable, and it doesn't make much difference what track we are on.

"I'm not able to enter the corners hard on the brakes, and we can't hope the situation will change completely with the new Bridgestone tires. These aren't problems you can solve with set-up alone."

Team manager Vittoriano Guareschi emphasised that the aluminum-frame GP12 project is still in its very early stages of development.

"It was a challenging weekend for our team, but we can also look at some positive aspects as we continue to focus on working with the still-young GP12," said Guareschi.

"Valentino had a difficult qualifying session, and he had problems in the race, particularly in the early laps with fresh tyres. We must learn how to solve this, because in the end he posted some good times."

Top Ducati rider Hayden was 28 seconds from victory, one-second further back than he had been in 2011. The American finished eleven seconds behind fifth place Andrea Dovizioso (Yamaha).

Rossi's best race lap was the slowest set by a manufacturer rider.

During winter testing, Ducati Corse boss Filippo Preziosi said that technical upgrades for the GP12 were not expected to be ready for several races.