Patson Daka will attempt to become Leicester's record European goalscorer on Thursday amid a sickness bug that has hit their hopes of beating Spartak Moscow.
Daka scored all four goals in last month's meeting in Russia to help the Foxes to a 4-3 win but they could be without both Harvey Barnes and James Maddison for the return game after the illness swept through the club's training ground.
Victory will keep the Foxes in the hunt to finish top of their group, which would send them straight to the last 16 and ensure they avoid February's play-off stage.