Chelsea have struggled without the influential midfielder's defensive cover, conceding 11 goals in his absence, and Conte acknowledged Kante's importance to the team ahead of the weekend's clash.
"He's progressing well... we also have tomorrow and then I'll take the best decision for him and the team. We are talking about an important player," the Italian told a news conference.
Conte added that the clash against second-placed United was a test of character for his men, as they look to reduce the gap between themselves and Jose Mourinho's side to one point ahead of next week's international break.
Fourth-placed Chelsea go into the game on the back of a 3-0 loss at Roma in the Champions League in midweek and Conte said his club were "struggling" to deal with their problems.
"If a period is positive, it's easy to have confidence. But in this moment when you're struggling it's important to show our character, to face the problem in the right way," he said.
"I'm happy to work with my players. In this season, we are struggling a lot. We'll see if you're a winner or a loser."
Mourinho had told his Chelsea counterpart that his antics in whipping up the crowd during last season's 4-0 league victory were "humiliating" but Conte said he respected the Portuguese and expected the same in return.
"It's not important the relationship. I don't like to speak about other situations. I have respect for the job. He's an opponent... after the game it'll be the same. I have respect for his job... he must have respect for mine."
Sunday's game will be the sixth time Mourinho takes a team to face his former side at Stamford Bridge as he targets his fourth win in all competitions against Chelsea.
(Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Christian Radnedge)
