Jorge Lorenzo has revealed that he feels physically "destroyed" by race simulations in MotoGP testing at the moment following winter surgery.
The double champion had follow-up operations during the off-season related to the damage he sustained in his pair of collarbone-breaking crashes at Assen and the Sachsenring last summer. He said his fitness was therefore hampering him in 2014 pre-season testing, where he has also been unsettled by the characteristics of Bridgestone's new tires.
"I underwent three surgery operations," Lorenzo told Gazzetta dello Sport. "I'm not in shape, I haven't had time to recover from the three general anaesthesia.
"I began gym work late and I'm far from last year's condition. I struggle to ride and a simulation destroys me."
Lorenzo played down speculation that his tough winter has made him consider his long-term future in MotoGP.
"When you are more stressed you think about quitting, while if you're enjoying yourself you want to keep going," he said. "It will depend on many things, but I'd like to carry on for four or five years."
He also emphasized that his preference was to stay with Yamaha – his employer throughout his MotoGP career so far – when his contract expires at the end of this year, but that it depended on the bike's performance.
"It would be romantic to end my career with Yamaha, where I've always felt well treated," said Lorenzo. "But as a competitive rider I'd like to have a bike as good as my rivals. I hope Yamaha can offer that to me before the end of the year."