Atletico Madrid are sweating over the fitness over striker Diego Costa ahead of their Europa League semi-final clash with Arsenal next week.

The former Chelsea star picked up a hamstring problem in the second leg of Atletico’s quarter-final win over Sporting Lisbon.

Costa limped off the field after 52 minutes with the injury on the night, and has since missed Atleti’s weekend win over Levante and has been left out of the squad for tonight’s meeting with Real Sociedad.

He will also miss the weekend’s clash with Real Betis, and his participation in next week’s Europa League clash with the Gunners is now in serious doubt.

Should he miss the tie, Costa’s absence will come as a huge blow to Atletico.

Since re-joining the La Liga giants in January, Costa has been in brilliant form and has forged a terrific partnership up-top with Antoine Griezmann.

Since returning to the Wanda Metropolitano, Costa has had a hand in nine goals – six of his own and three assists – while Griezmann has also thrived, scoring 17 goals whilst playing alongside Costa.

Arsenal however will be without their own superstar forward, Pierre-Emerick Aubameyang, who is cup-tied having played in the Champions League with former side Borussia Dortmund earlier in the season.