Defending MotoGP champion Jorge Lorenzo is out of Sunday's German Grand Prix after crashing heavily in a practice .

The Yamaha rider had surgery on his left collarbone on Friday after he broke it during practice at the Assen TT.

Just two weeks after breaking his collarbone, the yamaha rider flipped over the front of his bike on the fourth lap of the second practice session and landed on the back of his left shoulder.

After Thursday's accident Lorenzo was flown to Barcelona where he had a two-hour operation to insert a "titanium plate with eight screws to secure the fragments of the collarbone", surgeon Michele Zasa said.

Yamaha later issued a written statement that said Lorenzo planned to fly back to the Netherlands to spend the remainder of the grand prix weekend with his team.

Lorenzo is second in the standings behind fellow Spaniard Dani Pedrosa.

Stefan Bradl set the fastest time in the race of 1 minute, 22.030 seconds, with Lorenzo second quickest, his fellow Spaniard Dani Pedrosa third .

Source: Al Jazeera and agencies