Milan left-back The Hernandez made one of the most painful debuts possible when he came on to replace his injured brother as France trailed 1-0 to Australia.
The 25-year-old was not a starter in the match against Australia.
However, after nine minutes everything changed for Les Bleus.
Craig Goodwin scored for the Australians but Lucas Hernandez was badly injured and today it was confirmed that he has torn cruciate ligaments.
He was examined by doctors and replaced by his younger brother Theo, who made his eighth appearance for France, his first at the World Cup.
Bayern Munich’s Lucas Hernandez adds to France’s injury list, which is missing several players through injury including Milan goalkeeper Mike Maignan, Juventus midfielder Paul Pogba, Ballon d’Or winner Karim Benzema and Chelsea star N’Golo Kante.
