'Today I was in trouble, too, ' Sarri said afterwards.
"I had fever. It was a very hard day for me".
Freezing fog in Borisov contributed to an underwhelming display.
Maurizio Sarri's men welcome PAOK Thessaloniki FC in their next fixture at the Stamford Bridge and they will have the chance to field some fringe players since qualification has been sealed.
'It wasn't very easy to play a good game here. There was all the conditions to play very badly, for the cold, for the opponents, for the pitch, for everything.
Everton manager Marco Silva on his side's away form: "I don't have doubts that we will improve to the end of the season".
But Arsenal striker Danny Welbeck, given a rare start just hours after being named in Gareth Southgate's England squad, had to be stretchered down the tunnel with what looked a nasty ankle injury in the first half. I think we didn't play very well, I didn't like the first half because we moved the ball only horizontally and slowly, so it was hard to be risky.
Both sides were the beneficiaries of comical own goals in a insane first half which ended with Glenn Middleton putting the Scots 3-2 ahead, but Luiz Adriano and Sofiane Hanni both scored in the space of 71 seconds to snatch Spartak victory. We didn't manage the last 15 minutes well.
Hazard had been due to be off by then and Sarri was gesticulating wildly in his technical area, apparently towards the Belgian.
Emerson Palmieri crossed from the left in the 53rd minute and Giroud stooped to head in for Chelsea.
"I maybe lacked a bit of efficiency and a bit of luck sometimes, but you always need to keep working hard in training and keep the faith", the 32-year-old told BT Sport.