#4 Santi Cazorla (Arsenal)
Since his arrival in 2012, Santi Cazorla has been an instrumental part of Arsenal's plans. With his presence in midfield, he has the ability to take control of the game and chip in with goals and assists. He has the ability to adapt to the situation at hand and play different roles in midfield. Cazorla is also a leader on the pitch.
During his time at the Emirates, the Spaniard has been a part of two FA Cup triumphs in addition to becoming Arsenal's player of the season for the 2012-13 campaign.
Cazorla's absence has impacted Arsenal's form significantly. When he has been unavailable, Arsenal's win ratio and goals per game have come down in a manner that can be likened to a landslide.
However, for over a year, Cazorla has remained on the sidelines. He injured his Achilles tendon in October 2016. He has endured eight operations since the time he suffered the injury and was left out of the Premier League squad this season.
However, surprisingly, he has been added to the Europa League squad for the knockout stages of the competition.