4. Return for Augusto?
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Augusto Fernández has been on the sidelines for over a year after a debilitating ACL injury in September of 2016 against Deportivo La Coruña. Now, he's been included in the squad against Qarabag, something Diego Simeone would not do unless he trusted that the Argentina midfielder was back to full fitness.
Before his injury, Augusto had been a bright spot in Atleti's midfield following his move from Celta de Vigo. The 31-year old is good with the ball at his feet, capable of making the right passes at the right time, something which should relieve Koke of his creative duties a bit. His endless stamina enables him to lead Atleti's press, something that Gabi is usually tasked with.
After their transfer ban, Atleti's midfield depth is incredibly shallow. Only Gabi, Thomas, Koke, and Saúl are natural midfielders. The latter three are still young, meaning that Simeone has to be careful about playing them too much, while Gabi is 34-years old and is losing his consistency which made him a bastion of Simeone's midfield for so long.
Augusto could step in after a long injury layoff and show that he's still capable of dictating Atleti's midfield.