Rookie MotoGP title leader Marc Marquez has received plenty of plaudits after a stunning start to his premier-class career.

But praise that is sure to matter more than most came from triple 500cc world champion and former MotoGP team owner 'King' Kenny Roberts Sr, back in the paddock at Indianapolis on Friday, when Marquez led both practice sessions.

Marquez currently leads the world championship by 16 points, having has won three of the nine races so far this year and finished off the rostrum just once.

Roberts is also the only rider to win the premier-class title in his rookie season, a record Marquez has a chance of matching.

"I think the highlight, of course, is Marquez, who has just come out blazing," Roberts said of MotoGP 2013. "It's been a long time since we saw someone just come into MotoGP or grand prix and lit it up. And he's lit it up. To see that, I think it's a pretty special time.

"If you've ever watched it on TV or watched it in person - this kid's lit up the talent level quite a bit. It's actually changed things perspectively for people like me who watch it."

Roberts himself changed many things about motorcycle racing, not least claiming his place in history by being the first American 500cc world champion with consecutive titles in 1978, 1979 and 1980.

"Our era was a little bit more dangerous. So maybe we weren't at the limit everywhere as we could be. These guys are at the limit no matter where they're at," said Roberts. "Obviously, that limit is a pretty fine line between picking a hay bale out of your ass and staying on top of it. You never know what's going to happen. There's a very fine line between riding that thing across the finish line and getting into the grass."

'King Kenny' recently told the official MotoGP website that he was working on plans to return to the paddock as a team owner:

"We're working on something quite big - it's going to happen or it's not going to happen. When we come back we'll come back in a big way! And if you don't see me, you'll know we didn't get it done... Any longer than the next month or so [and] I don't think it's possible for '14."

Be there! CLICK HERE to see ticket prices for the remaining rounds of the 2013 MotoGP World Championship from the Official MotoGP Ticket Store.