#4 Gelson Martins (Atletico Madrid)
In the early weeks of June and July, Arsenal were heavily linked with a formal approach for Sporting Lisbon winger Gelson Martins.
Martins, 23, was set to become a free agent after being one of nine players to rescind their contracts - the club's well-documented player struggles saw many key players unhappy and angle for moves away across Europe.
He scored 13 goals and created 13 more across all competitions, as Sporting finished third in Liga NOS and were knocked out of the UEFA Europa League by eventual winners Atletico Madrid at the quarter-final stage.
Despite his obvious ability, reported interest died down as he was focused on helping Portugal at the World Cup and not immediately thinking about his future at club level. He made one appearance, a substitute cameo against Morocco during their group stage victory, as Fernando Santos' men were knocked out at the Round-of-16 by Uruguay.
Emery was said to be heavily interested, but Atletico announced they signed him on a five-year deal in late July.