Chelsea, where Villas-Boas was in charge for nine months last season, created history this week by becoming the first club to hold the Champions League and Europa League simultaneously.
Shortly after defeating Benfica 2-1, Rafael Benitez claimed that his successor, widely expected to be Jose Mourinho, will have £100million to spend in the summer.
The Blues already have the likes of Oscar, Juan Mata and Eden Hazard, whom Spurs were interested in last season, while both Manchester clubs face uncertain futures because of the departures of Sir Alex Ferguson and Roberto Mancini.
Villas-Boas thinks therefore that Chelsea, under the experienced leadership of Mourinho, would be favourites to win the Barclays Premier League.
"I think Chelsea next season will absolutely be the team to beat, bearing in mind the manager change and the manager that we expect to come," the Tottenham boss told a press conference.
"Plus they will be strengthening an already very good squad.
"I think they will be the favourites."