Kante has been injured for a month. Chelsea will be curious about how strong he will be able to play from now on. If this injury affects his performance badly then Chelsea might not think of extending his contract. Kante has always been an important part of this team so far. However they can find a solid alternative to him too in the end. Kante will need to convince them not to do so by his effort. Normally I don't doubt him but this injury period has been quite long. Let's see what he can do after his return on September 15.
Sure. Getting injured for a long time is very possible to affect a player's performance. It depends on how the effort of Kante to play again with his best form. If Kante has a strong intention to perform again at his best level, I think it is not impossible to see Kante play again in his previous form. As far as I know, Kante is a hard worker. He is a typical player who always pushes his performance to the next level. Because of this, I am not afraid that Kante will play again at his best level. And I am pretty sure that Chelsea will extend his contract as expected.