#3 Toby Alderweireld

One half of perhaps the best central defensive pairing in Europe with Jan Vertonghen, Alderweireld is one of the strongest natural defenders in football currently. His calmness and control positively affect Spurs whenever he plays.
After being a virtual ever-present over the previous two seasons, the Belgian has managed only 10 league appearances so far this campaign, due to a hamstring injury, and Spurs have suffered without the solidity of their usual partnership in that position. Alderweireld is 29 now and has talked about moving elsewhere.
He has unfinished business, for example, in Spain, after he couldn't gain a regular place in Diego Simeone's title-winning side of 2013/2014. He could fit into any defence in Europe, and the player knows it, and it's more than likely that Vertonghen will be left without his partner from next season.