Atletico Madrid left-back Filipe Luis is set to miss the remainder of the season and is a major doubt for the World Cup after it was confirmed that he fractured his left fibula during Thursday's 5-1 Europa League victory at Lokomotiv Moscow.

Filipe suffered the injury during a second-half challenge with Lokomotiv's Portugal international forward Eder, and subsequently left the stadium on crutches before flying back to Madrid with his teammates.

The club released a statement on Friday morning saying the Brazil international confirming the extent of the injury.

"Once in Madrid, Filipe Luis underwent radiological tests to understand the severity of the injury in his left leg," the statement read. "The medical staff can confirm the Brazilian left-back has fractured his left fibula. Filipe had to be taken off in the second half of the match against Lokomotiv Moscow after suffering a strong hit to his left leg."

The defender is now almost certain to miss the rest of Atletico Madrid's season, while the injury also puts in serious doubt any chance he could make Brazil's World Cup squad this summer.

Atletico Madrid confirmed Filipe Luis broke his left fibula during Thursday's win at Lokomotiv Moscow. Getty Images

Filipe, generally second-choice for Brazil at left-back to Marcelo, had been called up by Brazil coach Tite for this month's friendlies. The injury opened a spot for Juventus' Alex Sandro to be added to the squad.

Filipe missed the 2010 World Cup after suffering an ankle injury with Deportivo La Coruna, then was left out of the 2014 squad as Luiz Felipe Scolari opted to include Maxwell instead.

"Thank you very much for all the support," Filipe wrote on Instagram. "A lot of people said it was bad luck, but I think it was the opposite. I am very lucky to have a challenge in front of me and feel the love of so many people, and see that there is a lot of good in the world and that people unite to help others overcome their challenges."

Atletico coach Diego Simeone has other mounting injury concerns ahead of Sunday's La Liga trip to Villarreal, with right-back Juanfran substituted at half-time on Thursday with a muscle issue. Atletico confirmed that Juanfran injured a hamstring, but did not say how long he will be sidelined.

Forwards Kevin Gameiro and Diego Costa missed the trip to Russia with hamstring and ankle issues, respectively, while first-choice goalkeeper Jan Oblak was rested as he manages a glute muscle problem.

Simeone was already dealing with having only 19 senior players after midfielders Augusto Fernandez and Nico Gaitan, forwards Yannick Carrasco and Luciano Vietto, and goalkeeper Miguel Angel Moya all left the club in recent months.