Andrea Dovizioso has remained tight-lipped on the exact reasons behind halting contract negotiations with Ducati in mid-August and ultimately walking out of not only the team but a place on the 2021 MotoGP grid.

But after his final Desmosedici race at Portimao, Dovizioso suggested one of the factors was being "disappointed" at the reaction of "some people in Ducati" after finishing title runner-up to Honda's Marc Marquez in 2017, 2018 and 2019.

After four MotoGP seasons with Honda, then a single year at Tech3 Yamaha, Dovizioso was hired by Ducati for 2013, taking over the seat vacated by Valentino Rossi.

At the time, Ducati was a factory in turmoil, having gone through a series of countless human and technical changes fuelled by increasing desperation at being unable to win a single race with the nine-time world champion.

Even worse was to follow, Dovizioso's debut season (alongside Nicky Hayden) saw Ducati's results hit an all-time low as the factory failed to take a single rostrum for the only time since joining MotoGP in 2003.

It's against that yardstick that Dovizioso judges his 14 race victories, 40 podiums and triple title runner-up achievements that eventually followed.

"Very, very positive," Dovizioso said of his time at Ducati. "I think how happy you can be about something is from where you start. Everybody forgets that and it's difficult to remember how the situation was 7-8 years ago. But I remember very well. So yes, I'm so happy about that.

"For sure we couldn’t win the title and that would have been the perfect situation, but I'm happier than some people in Ducati and that is something really I'm disappointed [about], because we didn’t celebrate and we didn't live the special three years in a normal way. Not in a special way, in a normal way.

"This is something I'm not happy about. Disappointed. And every situation can affect the decision and the reason why we are in this situation [of leaving Ducati]."

Dovizioso added: "I will miss a lot of things because I have a really good relationship with some people inside Ducati, my crew, because when you live eight years with some people and have some nice victories the relations become very nice and for sure I will miss a lot of things.

"But in another way, I also feel 'light' because, as I explained in the past, there is something I don’t like that much in this situation. So to finish this situation, I feel light. I feel okay. I don’t feel 'well, I really want to continue in this condition'."

Dovizioso came into the final round holding sixth in the world championship but a typically canny ride from twelfth on the grid allowed him to reach sixth and vault past both Maverick Vinales and Fabio Quartararo for fourth overall in the championship standings.

Dovizioso was also just four points shy of Suzuki's Alex Rins, in third.

"I'm happy because our target was to finish fourth in the championship and we did it, and starting from 12th is very difficult because I had to fight with five riders in the championship," Dovizioso said.

"At the end, we could almost finish third, but finishing this season in fourth is further confirmation that my mentality and approach to the championship worked.

"But if I look back to before the season began, no [we can't be happy], because we wanted to fight for the championship for sure."

Dovizioso stood on the MotoGP podium an average of almost nine times per season during 2017, 2018 and 2019. So when Marquez was injured at round one, Dovizioso became the title favourite, at least on paper.

But his podium tally plummeted to just two rostrums in 2020, including the Red Bull Ring victory, as he and Ducati battled with the new grip characteristics of the revised Michelin rear tyre construction.

"It's impossible to transmit to people the feeling you have on the bike," Dovizioso said of the difficulties faced this year. "When that feeling is bad, in every track, in every condition. In practice you are always at the back. You fight in qualifying, you are always at the back. In the race I'm able to gain a lot of positions sometimes, but not riding like in the past. It's difficult.

"I didn't like this way to ride this year, especially because in the last three years I did something really nice. So related about that [bad] feeling, fourth is a really good position. But for sure it’s not an important final result."

Having also elected to turn down MotoGP testing offers, Dovizioso maintains he has his sights set on trying to return to the grid in 2022.

While Dovizioso was again the highest placed Ducati rider in the world championship, as he has been every year since 2013, Jack Miller (joining the factory team next year) finished second in Sunday's race allowing Ducati to lift the 2020 constructors' crown.

Dovizioso team-mate Danilo Petrucci, joining Tech3 KTM next year, finished 16th.