Andre Villas-Boas believes Tottenham "have to" finish above Arsenal this season to get fourth spot.
The last time Spurs finished above the Gunners was in 1995 - before manager Arsene Wenger took charge.
Asked ahead of the north London derby this Saturday if that was a realistic target this season, Villas-Boas said: "We have to.
"By what I see, it's obvious that Man United, Man City and Chelsea are into a big running towards the title."
- Tottenham have lost only one of their last five north London derbies to Arsenal, their 5-2 away defeat in February
- 100 goals have been scored in 32 derbies since Arsene Wenger took charge of Arsenal
He added: "To play for that fourth spot, I think you know it's difficult bearing in mind the amount of competition you have to beat."
Tottenham are currently in seventh place in the Premier League table and a point ahead of the Gunners after 11 games. Spurs are seven points behind third-placed Chelsea and 10 behind leaders Manchester United.
Last season Arsenal finished third and Tottenham fourth, but Spurs did not qualify for the Champions League due to Chelsea's victory in the Champions League.
Yet former Chelsea boss Villas-Boas, who takes charge of his first north London derby, believes Tottenham are getting closer to Arsenal.
"Recently, they have obtained more Champions League qualifications, so our objectives for the season have been within their reach for the last couple of years.
"We are certainly getting nearer in terms of what we are doing for the club, but the past shows that at the moment they are regular in obtaining those sorts of objectives."
Villas Boas also confirmed Belgian playmaker Mousa Dembele remains ruled out with a hip injury, after it had been hoped he would return.
Dembele, 25, who scored on his debut for Spurs in the 1-1 draw against Norwich, has missed the club's last eight games.
Villas-Boas said: "Dembele does not have a chance, not for this game. There is a 50% chance he will be back for the Lazio game."