Wesley Fofana was carried off on a stretcher after suffering a potentially serious injury during Leicester's pre-season friendly against Villarreal on Wednesday.
The injury to Fofana's left leg occurred after a scissor challenge by Villarreal forward Nino during the second half, with Leicester leading 3-0 at the King Power Stadium.
Fofana immediately called to the bench, with physios and paramedics rushing on.
Following a lengthy period of treatment, Fofana was stretchered off to applause in front of a crowd of over 17,000 fans.
The 20-year-old French defender established himself as a key player for Brendan Rodgers' side in his debut Premier League campaign last season, making 38 appearances in all competitions.
Leicester won the match 3-2 after goals from Caglar Soyuncu, Harvey Barnes and Ayoze Perez.
The Foxes, who won the FA Cup last season, play Premier League champions Manchester City in the Community Shield on Saturday, before they open their league campaign at home to Wolves on August 14.