Twelve of City's squad have played international football over the past fortnight and Guardiola concedes some of them are tired.
The fitness issues do concern him but the Spaniard, whose side face Crystal Palace in the Premier League on Saturday and play Borussia Monchengladbach next week, knows he has to find ways to cope.
He said: "As quickly as possible (we need them) involved again in our reality, but they need time
They are human beings.
"Today the schedule is so stressful for the players
I rest but the players don't
It is so demanding - 11 months and after that two or three weeks off and then 11 months again, and you cannot lose or play badly.
"That is why you have to handle that sometimes
When you see they are down, take them up, but every player is different.
"When some of them come back from the national team their regeneration is quicker than others, for the physical condition, for many many things.
"I am still getting to know my players, how they react after that situation, but it is important they come back good.
"We have a game and a final in Germany in three or four days and three days later we have Burnley, so everyone is going to play."
In this instance Guardiola said he had no fresh injury concerns but that his South American contingent - Sergio Aguero, Fernandinho, Nicolas Otamendi and Pablo Zabaleta - were feeling the strain most.
He said: "All the players came back good, fit but the players who played 90 minutes and (another) 90 minutes are tired, especially the South American players."
City slipped up on their last outing, conceding a late equaliser to Middlesbrough to lose top spot in the Premier League.
They have won just one of their last five games in the competition and Guardiola expects another difficult game against Alan Pardew's Palace at Selhurst Park.
He said: "(It is a) really tough game, (and a) coach with a lot of experience in England
They play a lot with (Christian) Benteke, second balls with all the wingers, with (Andros) Townsend, (Wilfried) Zaha.
"They are fast and good one against one, (Yohan) Cabaye is an exceptional player.
"The toughest games we will play now (are) away but we know the situation
We want to be there and stay there with the big teams in the Premier League
We have to win."
Palace are 16th in the table having won just three times in 11 games but Guardiola claims that is irrelevant.
He said: "When I see a team I never look at the position of the table
I see the games, I try to analyse what they do and especially when they play good, they are strong, it is not easy.
"They cross a lot and Benteke in the box is unstoppable, but every game is different."
Source : PA
Source: PA