"He has a problem with his hamstring, but I think I made a mistake, he should have rested today". That was Sarri's reponse following N'Golo Kante's injury that will put him out for at least two games.
Sarri opted to start Kante just three days after Chelsea's 1-1 draw with Eintracht Frankfurt in their Europa League semi-final first leg. The midfielder already had a hamstring issue which has now been worsened.
"Sometimes it's difficult to put someone on the bench so important like Eden Hazard or Kante - it's a risk.
"We will wait for the morning, it's very difficult to recover for the next two matches. We have to recover him for the final."
Sarri also gave reasoning behind Chelsea's slow start against Watford, saying the squad was tired after the quick turnaround from the midweek Europa League game.
Chelsea will hope that their key players are back to full fitness as they look to reach the Europa League final and continue their fight for a top four finish in the Premier League.