Aguero was stretchered off during the second half of the 2-1 victory at San Mames with an ankle problem and Atletico will be keeping their fingers crossed that tests do not reveal anything serious.

Atletico start the defence of their Europa League title against Aris Thessaloniki on Thursday and then host Primera Division champions Barcelona in the league next weekend before then travelling to Valencia the following Wednesday.

Sanchez Flores said after last night's game: "Kun (Aguero) suffered a significant blow and it is a tough toll to pay for these three points. We hope that the tests give us good news."

Atletico received encouraging news regarding Aguero after the 22-year-old underwent medical tests on his leg injury today.

Although the Argentina international will miss the midweek European match against Aris, there remains a possibility that he will be able to face Barca at the Vicente Calderon next weekend.

Speaking about the prospect of Aguero lining up against the Catalan side, Dr Jose Maria Villalon said on Atletico's website: "It's very difficult, but we are going to step up the therapy so that he could make the game.

"It's a possibility. At this moment it's difficult, especially as it still hasn't even been 24 hours since the injury occurred. However, right now we are not ruling him out for the game against Barcelona."