Valentino Rossi will resume his bitter feud with Marc Marquez in Argentina on Sunday, 12 months after he accused the world champion of "destroying the sport" when he was shoved off the track at Termas de Rio Hondo.
Rossi came to grief on his Yamaha at the hands of his long-standing Honda rival in 2018 in a move which resulted in a 30-second penalty for the Spaniard.
Marquez's attempts to apologise to the seven-time world champion were strenuously rebuffed even if the drama failed to prevent him from eventually going on to secure a fifth MotoGP title.
"This is a very bad situation, because he destroyed our sport, he doesn't have any respect for his rivals, ever," said a furious Rossi, adding he was "scared" to be on the same track as Marquez.
"When you go 300km/h on the track, you have to have respect, you have to be strong, you have to make the maximum, but doing it like this is over."
"If all the riders race like this, then this is a very dangerous sport and it will finish in a bad way."
In a rain-affected race in 2018, it was Britain's Cal Crutchlow who emerged the unlikely winner in Argentina.
Honda rider Crutchlow was third in the 2019 season-opener earlier this month behind Ducati rider and race winner Andrea Dovizioso who edged out second-placed Marquez in a thrilling finale.
Marquez has taken pole position at Termas de Rio Hondo on four occasions since 2014 and claimed two wins.
Rossi was third overall in the championship in 2018 - his 20th season in the elite class - but for the first time since 2012 he ended a campaign without a race win.
"Last year's race was incredibly tricky, riding on a half-wet, half-dry surface - it was very difficult to ride the bike with slicks over the wet patches," said Rossi who won in Argentina in 2015 followed by two second-place finishes.
Dovizioso, relieved after his Ducati was cleared of a technical breach, has struggled in Argentina.
The 33-year-old has only finished inside the top five once in the five visits and that was four years ago.
"We have started the world championship in the best possible way said.
"But the season is long and experience has taught us that cannot let our guard down."