Andre Villas-Boas knows Tottenham will be in for a supreme test when they meet Manchester United on Saturday evening, particularly after the summer addition of Robin van Persie.
The Dutch striker joined the Red Devils from Arsenal for £24 million during the transfer window, and has already found the net on five occasions for his new club.
Villas-Boas has cast his eye over Sir Alex Ferguson's reinforced squad with envy, especially after the Spurs manager struggled to recruit additional strikers of his own over the course of the summer.
The Portuguese concedes Spurs can't compete with United when it comes to attracting players with the pedigree of Van Persie, and says Ferguson has sent out a signal of intent with the acquisition of the Arsenal captain.
"When you can afford to buy one of the best strikers in the Premier League and further strengthen a squad that is already so good, it sends a strong signal to everybody," Villas-Boas said.
"A United team that can call upon van Persie, Chicharito, Danny Welbeck and Wayne Rooney will make it difficult for any opponent.
"It shows an intent from them to play with two strikers up front in the future and it is a massive attacking option that they have. United can put you into very difficult positions when players of this quality are performing well."
United host Spurs at Old Trafford in Saturday's late kick-off and Ferguson may be tempted to pair Van Persie with Wayne Rooney after the latter returned to action on Wednesday.
Rooney had been sidelined for over a month after suffering a gash to his right thigh, and completed 76 minutes in the Capital One Cup defeat of Newcastle.