Friday at Aragon will see 2006 world champion Nicky Hayden back on a MotoGP bike for the first time since leaving the series at the end of last year.
Now competing for Honda in World Superbike, the American has been called-up as a replacement for the injured Jack Miller at Marc VDS.
"Yeah, very excited," said Hayden, speaking in the Aragon paddock on Thursday. "Of course I'm also very curious to see - the track I already know - but the bike, the team and everything are new.
"I'm very curious to have a go on one of these bikes again. I mean, I like Superbike, but it's not like riding a MotoGP bike! So I hope I can get a good feeling and be quick enough to be able to push hard enough. Get close to the limit, to where it's fun."
Although it's been less than a year since Hayden last raced in MotoGP, major technical changes have seen Michelin replace Bridgestone as exclusive tyre supplier and the compulsory use of 'unified' electronics throughout the grid.
"I rode Michelins from 2003 until 2008, five years, but quite a while ago," Hayden said. "Seems like the tyres have changed a lot. Really until I try them I don't have a whole lot to say, they look the same - still black! But I always liked Michelins. I like a little softer feel to be honest, so I'm curious to see how I can get on with them."
Hayden also knows the MotoGP prototype will be more physically demanding that his usual Fireblade machinery, but is fit and ready for the challenge.
"There's no doubt, I ain't gonna lie, that Superbike is easier. Straightaways are a lot longer on Superbike, believe me!" smiled the 35-year-old. "Even the whole track - the ones we do [that also host MotoGP] - they just feel bigger now when I go back on Superbike.
"So I'm expecting to get a work out, but I'm healthy and got no excuses for my fitness. But it's true the races are longer. It's not going to be a cakewalk. Luckily this ain't Laguna or Jerez. It's pretty flowing. Long straightaways."
MotoGP is currently enjoying a record-breaking run of eight different riders winning the past eight races. Now watching the races as a fan, Hayden says the sport is in a great place.
"MotoGP is really I think in a great place," he said. "I mean this year has been incredible, who would have ever guessed that many different winners. Okay the weather played into it but still gotta win the races and it's been quite unpredictable.
"Rossi is still the star of the show, which is great for everybody, and some new faces. I think the racing has been really exciting and that the electronics have made a big different. It don't look like it's got any easier, it's as tough as ever, but as a fan it looks good."
Hayden battled with uncompetitive machinery in the now defunct Open class during his final two seasons in MotoGP, but said he doesn't regret leaving when he did.
"Not really. I've got a good home now in Superbike. A good opportunity. I had my chances here. I got 13 years," said the #69.
"This isn't a comeback or nothing like that, to be clear!" he added. "Superbike is my home now, my goals are there. But the chance to ride a good bike with a good team. Honda Europe was also behind the idea and, you know me, I wasn't going to say no!
"So here I am."
By Peter McLaren