Petrucci has been drafted in to replace the injured Enea Bastianini at Le Mans, who is continuing to recover from a broken shoulder that has ruled him out of every weekend since Portugal.
The double race winner competed with Ducati from 2015 to 2020, spending his last two years with the factory squad, where he scored both of his grand prix wins – at Mugello in 2019 and Le Mans in 2020.
Petrucci effectively retired from MotoGP at the end of 2021 following a year with Tech3 KTM, and has undertaken campaigns at the Dakar Rally, MotoAmerica and now World Superbikes.
Competing in WSBK with Ducati-backed Barni Racing, the Italian was told about his MotoGP call-up by the factory squad on Friday at last weekend’s Catalunya round.
“This is another thing I was not expecting in my life, but in the last year I did really a lot of things,” Petrucci said when asked by Autosport on Thursday at Le Mans how it felt to wear factory Ducati colours again.
“This time, I’m really happy and proud. Last time I was here with Ducati I won the race, so really good memories.
“I just can be really thankful to Ducati who allowed this. It’s quite a mission impossible, because jumping into a race weekend with no testing is something quite difficult.
“I think it will be a little bit easier compared to last year in Thailand, everything was really new except for the track.
“At least this time I already had one briefing, we have quite a [good base] set-up. I know all the team, I know the bike, which has even improved from three years ago.
“Superbike riders are testing now in Misano, but when they ask you to ride the bike that won the world championship last year, you can’t say no to this offer.”
Petrucci’s one-off appearance comes two weeks after Dani Pedrosa made a wildcard outing at Jerez, where he finished sixth and seventh in the sprint and the main race.
But Petrucci feels replicating Pedrosa’s Jerez form is not realistic for him at Le Mans.
“I wish so, but Dani is Dani,” he added. “I think he did a lot of kilometres on this bike in Jerez, and I think no one can learn something from Dani in Jerez.
“It was like he was in his backyard. For me, Le Mans is because I’ve been on the podium three times in a row.
“But now I think these guys in MotoGP are really fast. From what I understood, we can use the set-up I had three years ago and the bikes are going in that direction.
“So, maybe because of my size, already three years ago I was on the path for this type of set-up.”
Despite having been off the bike since 2020, Petrucci says the seating position is identical to how it was when he last rode it, which he thinks will help him to have an easier start to the weekend in FP1.
“Fortunately, they still have all the data from 2020, and also the riding position we can still use,” he said.
“So, at the end it’s like I have my bike. They haven’t told me where the bike has changed, but I think the bike has changed a lot.
“For the start, we’re ok, but then I will need to make some kilometres to understand how the bike is.”
