Kante won two Premier League titles, with Leicester and Chelsea, playing in central midfield, but has been deployed out of position on the right to accommodate Italy playmaker Jorginho in Sarri's chosen style. When the ball is on the left, he has to stay very close to Jorginho.
"If you don't have the determination then maybe you don't have the character in the mind, I wanted to understand this".
While this was Sarri's first loss as Chelsea manager, he admitted that the performance was "a disaster" - a word he used thrice during his post-match press conference.
Prior to the start of this season, there were rumours that the Spaniard could be on his way back to Santiago Bernabeu due to his inability score plenty goals during the previous season. A problem to be immediately ready at 100 percent. But we have to understand why we played against Tottenham without determination.
"When he plays deeper, I see a world class midfield player".
'I have to think about everything because Saturday we played very badly, a match without determination, but we lost one match after 110 days, so the team did well, generally.
Kante's adopted a different position from last season, playing a more attacking role following the summer signing of Jorginho. On Monday they were all together, but the situation was similar. And I think this one is not one of the best characteristics of Kante.
Chelsea have an opportunity to respond against PAOK in the Europa League on Thursday, when a point will confirm their passage into the round of 32.
According to the Italian, Moses is now suffering from a back injury, while Hazard picked up a slight injury.
"The problem was with the approach in the last three matches", said Sarri.
Sarri said: "I am anxious because 25 days ago he had a back injury".
As much as it appears to be a mere consolation, his goal against the North London club is definitely sounding a warning to Morata - sit up and regain his form as soon as possible or you lose your place in the team - and a message to Sarri - don't look elsewhere, I'm Morata's flawless replacement. So it's normal he wouldn't be top of his physical condition.
"The numbers will be big and I think he's not quite there yet in terms of being a ready-made impact player".