Kante trudged out of the Stamford Bridge clash after little more than half an hour, complaining of twinges in his hamstrings.
The World Cup-winning midfielder has been in sparkling form at the end of this campaign and boss Tuchel has admitted Kante’s presence can transform the Blues.
Toni Rudiger’s bundled goal and Jorginho’s penalty helped Chelsea see off Leicester, to avenge Saturday’s FA Cup final defeat and inch the Blues towards a top-four league finish.
Tuchel was delighted with the result, but quickly admitted Chelsea are left to sweat on key man Kante’s fitness - with the final league fixture at Aston Villa and the Champions League final still to come.
“I hope that N’Golo is not injured, he told me that he went out before injury,” said Tuchel.
“He felt his hamstring and was worried that he would get injured if he continued to play.
“So we put Mateo Kovacic in, which was also a huge risk. We had planned to put him in only for 20 minutes. But we had to put him in for 60 instead.
“So we took some risks but it was absolutely the moment to take risks, in a game of the highest importance at the end of the season.
“We are a different team with and without NG, but we can also manage to adapt.”
Win at Villa on Sunday and Chelsea will book a top-four finish and qualification for next term’s Champions League.
Boss Tuchel insisted the Blues have no time to celebrate after a pulsating result, with their job only half done.
“It felt like a huge effort and a top performance,” said Tuchel.
“Don’t get me wrong, it’s a big step, but it’s only a step; it’s not done yet, we have to push it over the line on Sunday.
“Now is not the time for celebrations or praise; it’s three points but only three points and the job is not yet done.”
Chelsea leapfrogged Leicester, who face Tottenham on the final day when they will require a victory to push into Champions League qualification.
And Foxes boss Brendan Rodgers admitted his side wasted several chances to secure what would have proved a vital draw, most notably from Ayoze Perez late on after Kelechi Iheanacho had pulled a goal back.
“We knew it would be tough off the back of the weekend,” said Rodgers. “We knew we’d have to weather the storm.
“We could have been better with the ball and played forward a little bit more.
“We’re disappointed with the goals we conceded.
“Our idea was to make sure we stayed in the game. But we gave away a soft corner, and the second one looks very, very harsh for the penalty.
“And Ayoze will know with his late chance that he could have done better.”
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