With six races remaining, starting with Sunday's Singapore Grand Prix, just 22 points separate the pair as they fight it out for the sport's most-prized trophy.
Reflecting on what has unfolded between them on-track this season, Wolff concedes there has been a noticeable deterioration in their roles as team-mates.
Speaking to BBC Sport, Wolff said: "It has changed from, let's say, an almost amicable relationship at the beginning of the season to a very intense moment, where it was almost like realising these two are enemies competing for the world title.
"It's also a learning process. These boys have been calibrated their whole life that their main priority is to win the drivers' championship in F1.
"And here they go - they are in the same car, competing against each other for that trophy, and one is going to win and one is going to fail.
"This is a new experience for them - a difficult experience maybe."
On occasion Rosberg has shown a ruthless side to his nature, such as in Monaco during qualifying, and again in Belgium where he opted not to take avoiding action, instead colliding with the Briton and puncturing a tyre.
Wolff added: "There are 22 guys out there and all of them are ruthless. They know what they want and they will try to take it.
"Nico has always been like this. I don't know why anyone had the perception of him being Mr Nice Guy."Suggest a correction