#3 Toby Alderweireld
Toby Alderweireld was high on United's wish list last summer but Ed Woodward couldn't make a breakthrough in the negotiations for the centre back. Spurs then activated a clause which will now allow the Belgian to move to any other club for £26m in the final two weeks of the summer transfer window. With the inflated market, a move for him could prove to be a shrewd piece of business.
Not only does Toby possess some valuable Premier League experience but he is also arguably one of the best defenders in the Premier League. His reading of the game is immaculate which enables him not to dive into challenges. He has a calm and composed demeanour and is adept at playing defence-splitting passes from the back.
With the three-man defence system gaining prominence, signing Toby Alderweireld could give the gaffer the chance to play three at the back thus playing Luke Shaw and Diogo Dalot as wing backs and utilizing their attacking talents.