Thomas Tuchel to contend with a Chelsea midfield crisis.Kovacic had only just returned to training after an eight-game absence due to a hamstring injury.The 27-year-old Croatia international will now have to self-isolate for 10 days, meaning he is set to miss another three matches.
And he returns to the sidelines alongside several other Blues stars ahead of a busy festive period which sees them play seven games before the end of the year.Crucially, Kovacic is the third central midfielder Tuchel is without, as both N'Golo Kante and Jorginho are injured.Speaking ahead of the final Champions League group game away at Zenit, Tuchel said: "Mateo was in training yesterday with a big smile and was pure pleasure to have him back.