Former MotoGP champion Nicky Hayden admits he underestimated the scale of the challenge during his one-off return in last weekend's Aragon race, when he stood in for an injured Jack Miller.
Riding Miller's Marc VDS Honda machine, Hayden - who quit the series to move to World Superbikes last year - claimed a single point with a 15th place finish at Motorland after languishing towards the bottom of the timesheets most of the weekend.
Having never tried the new generation of Michelin MotoGP tyres introduced for this season, the American admitted getting up to speed with the French rubber was the most challenging aspect of the weekend.
"The race I would say was the best session I had all weekend," said Hayden after the race.
"I started too far behind on Friday to get the feeling with these tyres, and the bike, but we found a good direction last night [Saturday], the bike felt better this morning [in warm-up].
"For the race we didn’t touch anything. I got in there, I did a good start and I was able to race with some guys like [Danilo] Petrucci, [Yonny] Hernandez, the bike was working pretty good.
"The group in front of me with [Michele] Pirro I was hoping to come out on top of, but I went back and forth with Barbera a little bit, lost some time.
"In the end I got one point, of course I hoped I could do something better but I guess I underestimated how hard it was going to be to get up to speed with these tyres, particularly the front.
"I didn’t feel good with them, and they felt hard, so I went slow and it made the problem worse. The more confident you are, the faster they go and the better they work.
"And I didn’t really get that feeling until [Saturday] afternoon, so it’s a little frustrating. In the end it wasn’t a disaster, I got to race with [some] guys and have some fun battles."
Asked whether he felt any more cameo appearances in MotoGP would be possible, Hayden replied: "I don’t know, now I go back to World Superbike next year, and I hope next year I’m closer to the front.
"Honda Europe wanted me to come do it [replace Miller], so who knows? It’s another year in the record books of scoring a point in MotoGP, never say never. For now, this is Jack's bike, his team. It was just a one-off."
Hayden admits: "I underestimated how hard it would be"