Denis Zakaria was brought off for Ruben Loftus-Cheek in the second-half of Chelsea's clash with Dinamo Zagreb. The 25-year-old midfielder had enjoyed a superb debut under the lights at Stamford Bridge which was unfortunately brought to a premature end.
He was seen to perch himself down on the floor after seemingly feeling discomfort in his right leg. Upon being hoisted up by the Blues' medical team, the Switzerland international clutched at the side of his upper thigh.
After walking around the pitch with little to no aid from the medical staff, Zakaria beelined towards the dressing room, hinting that a knock is the reason for his substitution. The Swiss' injury comes as a major blow for Graham Potter as Chelsea are hit with another injury ahead of the blockbuster bout with Arsenal on Sunday.