Factory Yamaha's Ben Spies starts tomorrow's Sepang MotoGP round from the back row of the grid after two crashes in practice and qualifying today put paid to any hope of a good grid position.

The Texan is still suffering with the ribs he broke at Phillip Island and doesn't yet know what caused the qualifying crash but his mission is to try and get a decent points haul and stop Valentino Rossi going past him in the championship table.

"It’s been a pretty eventful weekend. The bike is working really well but I’m just not feeling 100 per cent and ready to get it over and done with. Qualifying was tough, we went out there and experienced a crash, I’m not sure why yet but we’ll check the data later. We don’t have a great position on the grid but we’ll do the best we can for points to try and hold on to fifth place for the Championship," said Spies.