The situation has eased massively, with the latest Premier League figures released on 14 February showing just two positives out of the 2,915 players and club staff tested over the previous seven days.
“The Premier League should be concerned about this,” said Guardiola.
“The only way to be protected from this virus is to stay at home and social distance. No contact, don’t travel, don’t move. Now the players are going to their national teams and it is difficult afterwards to control it. So, unfortunately, something is going to rise.
“I would love to say it is not going to happen but from experience, it happened in two or three waves already. If you move, you take a risk to be contaminated.”
The number of positive tests occurring between the October and November international breaks was lower than the week immediately before the first break.
However, numbers did start to rise after the November break, going from 10 to 14 before reaching a peak of 36 in the period from 4-10 January, which was around the time when Villa and Fulham were particularly badly affected.
World governing body FIFA has said clubs do not have to release their Portuguese and South American players, although it is yet to be seen whether that will be enforced, particularly if players express their own determination to represent their countries.
English travel regulations require passengers travelling back from a ‘red list’ country – including Portugal and Brazil – to quarantine in a hotel for 10 days on their arrival.