Andre Villas-Boas has tipped Chelsea to win the Premier League next year and admitted his Tottenham squad may fall behind their rivals unless they strengthen their squad.
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."
Unlike Benitez, Villas-Boas does not have the comfort of going in to Sunday's final round of matches knowing that Champions League qualification has been secured.
Indeed, only if Spurs beat Sunderland and Arsenal drop points at Newcastle will Villas-Boas be managing in the Champions League next season.
If Spurs finish fifth, Villas-Boas will have failed to deliver the Champions League qualification target set for him by Daniel Levy last summer.
The former Porto coach has done well to cope without Rafael van der Vaart, Luka Modric and Ledley King, though, and should his team win on Sunday they will end the season with 72 points - a record for the club in the Premier League era.
That total would have been enough to finish second on three occasions over the last 20 years and only once has a team finished fourth in the Premier League with more than 72 points.
The raising of the bar for top-four qualification means Spurs must strengthen their squad this summer, according to Villas-Boas.
He said: "I think what it represents, if we don't achieve it, is one more sign that you have to push up to get closer to that group.
"Whenever that group is competing for titles, the reference of points will be higher and you have to improve and you have to get more points the next time.
"Our step at the moment is to be into the Champions League, probably not title contenders but we hope to be competitive next season if we manage to do things properly in the summer.
"You have to strengthen for next season to get a higher tally of points."
Villas-Boas pored over the reasons behind his team's failure to hold on to their top-four place today.
Injuries to key players like Sandro, Younes Kaboul and Benoit Assou-Ekotto were cited while Villas-Boas also lamented points lost at home to teams like Wigan and Fulham.
Should his team finish underneath Arsenal for the 18th season in a row, he does not think it will have a big impact on Tottenham's ability to attract top players this summer, however.
"I'm not sure it's that key," he said. "Tottenham has a great tradition in football, it has conditions that other clubs don't have and great facilities.
"And I think we have a group of players that attract other players to come here."
Villas-Boas refused to rule out a move for Barcelona striker David Villa, the latest player to be linked with the north London club.
"He's one of the world's best strikers," Villas-Boas said.
"Speculation is growing here (about transfers in general), but at the moment we are focused on trying to get the fourth spot."
Tottenham's main goal this summer is to hold on to 25-goal forward Gareth Bale.
Spurs have a history of rewarding their top performers with new contracts, but Villas-Boas is unsure whether Bale is close to signing new terms, as has been reported recently.
"I'm not sure, our interest is for the player to continue here and I've made that very clear," he said.
"I have said this numerous times. We are pretty confident we will be able to keep him."