Mick Doohan has been surprised by Marc Marquez’ unrelenting form as a MotoGP rookie.

Five-time 500cc World Champion Mick Doohan says the meteoric rise of Spanish sensation Marc Marquez has been “fantastic” for MotoGP ahead of this weekend’s 2013 Tissot Australian Motorcycle Grand Prix.

Marquez, 20, comes to Phillip Island with a 43-point championship lead with three races remaining, meaning he could seal the title in Australia and become the first rookie to win the championship in 35 years.

Speaking to the Australian Motorcycle Grand Prix ‘Keeping Track’ podcast, Doohan admits he’s been taken aback by the success Marquez has achieved in a rookie season that has featured 14 podium finishes in 15 races and a win in just his second MotoGP outing in Texas.

“I knew he was quick, but the way he’s come in and maintained the momentum from the start,” Doohan said. “Having a few wins under his belt early really sent his confidence to the next level.

“I don’t think anyone would have picked how strong he’s been, but I think it’s been fantastic for the sport.”

Marquez, who won the Moto2 title in Australia last year, has come under fire on several occasions this season for his assertive approach, and clashed with Honda teammate Dani Pedrosa at Aragon in Spain in September in an incident that saw Pedrosa crash out soon after, all but ending his championship hopes.

Doohan feels Marquez’s aggression is acceptable as long as it remains measured.

“You need to have a controlled amount of aggression, and I don’t see that he’s out of control,” Doohan said. “For me, it’s not an issue.”

‘Keeping Track’ is the official podcast of the Australian Motorcycle Grand Prix, hosted by Matt Clayton and Mark Fattore.