MotoGP world championship leader Valentino Rossi is wary of the growing challenge coming from Marc Marquez heading into this weekend’s German Grand Prix.

The Yamaha rider extended his championship lead to 10 points after coming through a titanic scrap with reigning world champion Marquez to score a controversial victory at the Dutch Grand Prix two weeks ago.

While the nine-time world champion is enjoying a strong run of form of his own, Rossi expects Marquez’s charge to intensify at Germany’s Sachsenring.

Marquez, lying fourth in the standings, has struggled to replicate his form of the last two seasons, scoring just one race win so far in 2015.

However, a switch to a 2014 Honda chassis sparked an upturn in fortunes for the Spaniard at Assen, which Rossi believes will continue this weekend.

“I’m ready for Sachsenring and am going into this race weekend with a happy mindset,” said Rossi.

“I managed to recover a bit of an advantage that I had lost in past races.

“Having a 10 point lead after eight races is not bad, I’m very happy. Now we go to Germany and it will be very important to reconfirm how competitive we are.

“We understand that our competitors are working hard to return at the front and in Assen we succeeded in staying ahead.

“Marquez will probably be with us in the next races and we must be very careful with him.

“At Sachsenring my first goal will be to work as we have done in the Netherlands, starting from the first free practice.

“Jorge (Lorenzo) I’m sure will come back strong, making it even more important to work well this weekend.

“After Sachsenring there will be a break and it will be important to rest a bit before taking on the second part of the season.”

The grid will feature two changes this weekend with Northern Irishman Michael Laverty and Italy’s Claudio Corti set to join the championship.

Laverty has been confirmed as a permanent replacement for Marco Melandri, who has cut his ties with the Aprilia Racing Team.

Corti will substitute for Stefan Bradl at Forward Yamaha with the German forced to miss his home race through injury.