Hamilton admitted in 2019 that "you always leave Max a lot of space, it's the smartest thing you can do".
"Now we're in a very different situation," said the 2016 champion of the Hamilton-Verstappen dynamic into the latter's seventh year on the grid.
"Now Verstappen is the number one rival and the elbows are coming out. I don't think Lewis is going to be backing out like he used to back in the day.
"I promise you Lewis has noted that Turn One in Imola. He will remember that and will be ready for payback.
Reflecting on the opening dramatic two events of the season, Rosberg said: "I think we're in for a fantastic season this year, because Red Bull vs Mercedes - and their cars are equally as fast and they have fantastic drivers fighting it out there on track.
"We're seeing wheel-banging between Hamilton and Verstappen already, and we're only two races in. It's going to be a great year.
"Max Verstappen is arguably as equally a phenomenal driver as Lewis Hamilton at the moment.
"Max has always had phenomenal speed, it's just that he was too aggressive and made mistakes a few years ago. Now he's really put it together, and the mistakes are just not there for Max anymore.
"He can really take it to Lewis."