Jorge Lorenzo feared he was left with a permanent disability

Jorge Lorenzo says he is relieved that injuries sustained in a warm-up session crash in Australia have not left him with a permanent disability.

The Yamaha rider has undergone plastic surgery to his left hand and will miss the Malaysian MotoGP.

As a result, the team have handed test rider Katsuyuki Nakasuga his MotoGP debut in the Spaniard's absence.

"After the crash I was very worried I would not have full feeling in my finger again," said Lorenzo, 24.

"With the excellent treatment I had, I have been assured I will have complete feeling in nerves and tendons."

The 2010 MotoGP world champion was injured before Casey Stoner took his title at the Australian Grand Prix. .

Lorenzo trapped his hand under his bike after being thrown off during the last lap of morning warm-up at Phillip Island on Sunday.

The factory Yamaha rider sustained injuries to his ring and middle fingers.

A decision is yet to be taken over whether Lorenzo will contest the final race of the season in Valencia, Spain, on 6 November.

Lorenzo added: "I am very proud of my team for all the hard work they have put in to take second in the championship.

"Now we have to think about next year and work as hard as possible to win again."

Yahama confirmed in a statement that Lorenzo was out of the Malaysian Grand Prix. They added: "The surgeon was able to save the nerves and tendons of the injured fourth finger and, as a result, no functionality will be lost in either the finger or the hand.

"A decision on the Valencia Grand Prix will be made dependent on Jorge's condition after his return to Barcelona."

Lorenzo's Yamaha team-mate Ben Spies also missed the Australia race after a crash in qualifying.

Yamaha said: "After attempting to ride some laps in warm up, the rider reached an agreement with team members that attempting the race with reduced concentration would be considered too dangerous for himself and other competitors."