Nico Rosberg has fired the opening salvo as his rivalry with teammate Lewis Hamilton is set to recommence.
The pair, once boyhood karting friends, endured a tetchy relationship last year as they battled alone at the front of the grid for the 2014 title.
Briton Hamilton ultimately won the day, but only after some notable low-points, including a crash at Spa and having accused his Mercedes teammate of deliberately running off the road during qualifying in Monaco.
"There were difficult times," runner-up Rosberg admits, "which is inevitable, and it will be that way again.
"But in the end, there is respect and we always found ways to communicate."
Indeed, after raising the 2014 trophy aloft, Hamilton claimed that tensions with Rosberg had finally cooled.
But Rosberg told Italy’s La Gazzetta dello Sport their relationship is no longer what it once was.
"I don’t think we’ll never talk again in our building in Monte Carlo," said the German, "but a couple of years ago, Lewis would come to my house for a hamburger.
"That doesn’t happen anymore," Rosberg revealed.