The Uruguayan, 33, has joined as a free agent after ending his seven-year stint with PSG.
And former United star Berbatov believes Cavani will either hit the ground running or ease himself into English football.
"I'm looking forward to seeing how Cavani will be used in the team, as a former striker myself I always wonder about strikers at United," Berbatov told Betfair. "I hear he could make his debut against former club PSG on Tuesday, he is their all-time top goal scorer, and that would be very fun to watch.
"If he's available, it will be interesting to see how he performs, it's not always so fun to play against an old team. Sometimes you think 'I'd rather not'. That said, there are other times when you have been let down by a club and you say, 'I'm ready, bring it on, I want revenge'! It will be interesting to see which way it goes if he does indeed play.
"It's fair to say he is in the twilight of his career, but even at this stage, there are games when you get the butterflies. Some games are more special, they are emotional, and even experienced players will feel this.
"When the end of your career is in sight, you want to play as much as possible, because you know there isn't too much time left. Cavani is only 33 however, and he will be fit. He is a lean guy. He may not be quite as good as his prime, but I have no doubt he can still have an impact.
"He has scored goals everywhere he has gone, but this is a new league, and new team-mates. I think one of two things will happen - he either hits the ground running immediately, or he will be a slow burner.
"The guys at United will want to help him straight away, they will want to feed him goals.
"Again though, if the team is not performing well, strikers usually won't score, so he needs the other 10 guys to start playing too. I hope he can hit the ground running, because United not only need to defend better, they need to create goals, and quickly."