Villas-Boas accepts the days of a straight two-horse race for English football's biggest prize look long gone.
"There are so many strong teams," he said. "You see the way Tottenham are playing, the ambitions and the revolution at Manchester City, Arsenal's hunger for success and the way last season slipped away from them for sure Mr Wenger will provoke them to respond in every fixture.
"The way [Manchester] United go about their business. They are not here to play, They are here to be successful.
"Even Liverpool, with the arrival of [Kenny] Dalglish mid-season, the way he built and revived Liverpool, just missing out on the UEFA Cup spot - big, big challenges lie ahead for us, and that is what we want to face."