The sad thing about Christopher Nkunku and Chelsea is this player joined Chelsea for a high amount of money from Leipzig in this summer. I'm sure Pochettino hired to have this player an effective player for the next season and getting injured, he is going to rest for two months and which can damage the team, now Pochettino should think about alternative players for him, however, he said they still need some a few days to check this situation and see if he can get recovered faster than usual or no.

Of course that was also not expected by Nkunku because injury is not something that players can avoid, and within 2 months of his resting, Pochettino must install another player for his position, because of course, Pochettino doesn't want what has been prepared to go bad just because of one player get injured
The first game will be important for Chelsea because they will have a big match against Liverpool, in the last few matches when the two teams have faced each other it has mostly ended in a goalless draw, but the many changes they have made of course their fans and their new coach expect something different they win if can, but beating Liverpool is not easy even though this is a home match for Chelsea, because just as Chelsea are trying to re-develop their team so is Liverpool.
In the pre-season matches the two teams got encouraging results but this will be different later because the pressure will start to be felt by the players of the two teams, so anything is possible.