Pep is aware that his squad is still good enough that he doesn't need much for next season as their current players are in a good enough range for a club.
Gundogan is gone but they are also potentially losing bernardo Silva and have already lost Kyle Walker in defence.
I think Pep will look for someone suitable again to fill the position Kyle Walker left behind.
But he's not in too much of a hurry on this because he's also aware that rushing things could lead to missteps. There are some rumours about Pavard as Kyle Walker's replacement now but these too are still just rumours.
But indeed talking about their performance, they still have a pretty solid squad on each line for their reserves, they also have some good players so this is clearly still in Manchester City's favour despite losing several players and for the Champions League they are still one of the candidates especially with their current condition as defending champions.
Losing Gundogan, Walker, Mahrez and the potential to be left behind by Bernardo Silva has not made Pep Guardiola dizzy with the current condition of the squad he has. The arrival of Mateo Kovacic can provide a solution in midfield and may be projected as a replacement for Gundogan. The calm demeanor appointed by Guardiola indicates that the squad currently owned can still be relied upon, it does not rule out that Guardiola will look for other quality players to add to Manchester City's strength.
Manchester City which has the status as the defending champion, must be able to give its best in the Champions League because the demands this season are heavier after achieving success last season.
That said, Pep's confidence level is actually very good and worthy of praise I think.
He always allows his players to leave or stay at the club for as long as their contracts last and that's the case for Bernardo, Mahrez and Gundogan at the moment.
In the case of Gundogan for example, Pep wanted him to stay but when Gundogan wanted to leave with his status and self-awareness that he would have difficulties from the competition for the line-up Pep understood and did not give a difficult thing instead he allowed it well because he realised that being forced to stay would also be useless and I like Pep's personality like this.
Players coming and going for a club is normal and Pep knows this, but on the other hand he also immediately thinks about his squad whether it is still capable or not and when he feels he is still lacking he immediately buys quickly as a replacement but when he feels enough he doesn't do much and gives more confidence to existing players.
As for the replacement of Kyle Walker, there are currently some rumours about Pavard who really wants to leave Bayern. There is also the name Hakimi who is currently being discussed as one of the successors to replace Kyle Walker for Manchester City.