Johann Berg Gudmundsson faces a race against time to be fit for Iceland’s second match of the World Cup against Nigeria on Friday.
The Clarets winger was withdrawn 63 minutes into Iceland’s 1-1 draw with Argentina on Saturday and it has now been confirmed that he has suffered a muscle tear.
Gudmundsson became the first Burnley player to feature in a World Cup since Billy Hamilton for Northern Ireland in 1982 and he helped Iceland to another historic result in what was their first ever World Cup game.
Assistant coach Helgi Kolvidsson said: “Johann Berg Gudmundsson has torn a muscle. It remains a question whether he will be fit but we’ll see on match-day.”