#2 Hector Herrera (FC Porto)

Hector Herrera is a 28-year-old central midfielder who currently plays for FC Porto in Liga NOS. He has also featured for Mexico's national team a total of 70 times since first making his debut in October 2012.
Herrera is by far the most experienced player on this list, having played in Mexico for much of his career before his move to Portugal in the summer of 2013 for a fee close to £10m. He is currently the captain of Porto.
What Herrera could bring to the Tottenham midfield is an air of stability and level-headedness, which Spurs have appeared to lack in recent months. Most of their squad is quite young, so the experience is still being gained; however, for someone like Herrera, who's already done it all, to join the squad would make a world of difference.
Herrera's market value is estimated at around £20m, though for Spurs to buy him, it might be more realistic to expect a fee of around £25m.