Marc Marquez says Jorge Lorenzo is the 'mystery' for the 2017 MotoGP world championship and casts doubt on whether he can sustain regular podium battles with Ducati.

The reigning MotoGP champion finished pre-season testing with frustrations after crashing three times on the final night of track action in Qatar to mark a tricky start with his RC213V ahead of the new season.

Marquez remains positive, explaining he feels better prepared for this year than last season, but is aware the season opener at Losail will pose a difficult track for Repsol Honda to prosper at.

Since the Qatari's track introduction in MotoGP in 2004 Honda has scored just three race wins with its most recent coming in 2014 when Marquez triumphed under the floodlights.

Looking over the 2017 season, Marquez fully expects the factory Yamaha riders and his team-mate Dani Pedrosa to be the title contenders but has put a question mark over Jorge Lorenzo at Ducati.

"We are starting out at one of the circuits that we have found more difficult, and that is perhaps less favourable for the characteristics of our bike," Marquez said. "However, we do not have to rule anything out and we will start with maximum motivation and ambition to see if we can fight for victory.

"More or less the same riders as every year [to fight for the title]. Rossi, Vi?ales and Pedrosa - who has had a very consistent pre-season.

"We'll see with Lorenzo, because he can have good races and the mystery is whether he can be fighting for the podium every Sunday, which will indicate if he can aspire to win the World Championship."

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Marquez is confident Repsol Honda has already arrived at a level it can battle for rostrum places at the unfavourable Losail circuit and is relishing the hunt for a fourth MotoGP world crown in 2017.

"We come into this season better than last season, but this does not mean that the result will be better," he said. "What is true is that we have prepared well. Physically I am at 100% and mentally I am also very motivated, as always, to try to fight for the title for another year.

"On a technical level I always want more; everything's never perfect and we always want to be better. Seeing how we were when we started the preseason, I think we have reached an optimum level to fight for the podium from the first races."

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