Tyronne Ebuehi has suffered a serious knee injury during Benfica's International Champions Cup defeat by Juventus on Saturday, the Portuguese giants confirmed on Monday.
A statement published on Benfica's website confirmed that the Nigeria international has suffered damage to his left anterior cruicate ligament.
The club also noted that the full-back will undergo surgery in the coming days.
The defender, who only signed for the the Eagles from ADO Den Haag on May 19, now faces a lengthy spell on the sidelines.
Ebuehi entered the ICC clash at the Red Bull Arena in the 67th minute, replacing Andre Almeida, with Benfica losing 4-2 on penalties to Juventus following a 1-1 draw.
22-year-old Ebuehi, who was a member of Nigeria's World Cup squad, signed a five-year deal with Benfica after leaving the Eredivisie.