Ballack told Goal. "But more importantly, you have to give him a vision".
'We felt that for him it's better to play, not for 90 minutes, but to play after two weeks of not playing. I had fever. It was a very hard day for me. "It is normal to look around and think, 'With what club can I achieve that with?'"
'But I don't want him to be anxious about scoring because, for us, he's very important and very useful.
The Stamford Bridge outfit also remain the only unbeaten side in Europe's top five leagues in all competitions following their win on Thursday evening.
"From our doctor, there is no risk [to select him]", Sarri said.
That will be a big incentive for Sarri and his squad, as with some big matches on the horizon and a busy Christmas period to come, to have the ability to rest as many players as he wants in the final two games safe in the knowledge that the results are not important, would be a nice luxury to have.
'It wasn't very easy to play a good game here. It had all the conditions to play very badly, with the cold, the opponents, the pitch, everything.
"The manager kept saying we need to finish first in the group, and the earlier the better so tonight we've done the job even if we could have been more efficient", he said.
He added: "I didn't like the first half". We moved the ball only horizontal and slowly.
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.