Manchester City boss Pep Guardiola is concerned the March international break could result in another wave of coronavirus positives for Premier League clubs.
City can go 10 points clear at the Premier League summit with victory over Everton at Goodison Park on Wednesday - a rearranged fixture after the initially scheduled December encounter was postponed due to a COVID-19 outbreak among Guardiola's squad.
Aston Villa also withdrew from action during the post-Christmas period and Newcastle United were affected similarly earlier in the season.
The Premier League responded by upping testing at clubs to twice a week and, in the most recent period returned, there were two positives from 2,970 players and club staff tested.
This represents a significant drop from 36 positives out of 2,593 tests between January 4-10 but Guardiola is wary of some of this good work being undone when his players and others begin travelling the globe again over the coming weeks.
City's Champions League last-16 trip to Borussia Monchengladbach has been switched to Budapest, with European games featuring Premier League counterparts Liverpool, Manchester United, Arsenal and Chelsea also switched from their original venues due to local COVID-19 protocols.
Asked whether the subsequent international matches next month will place members of his squad at risk, Guardiola replied: "Hopefully not but the only way to be protected from this virus is to stay at home and don’t move and social distance and no contact and don’t travel.
"Now the people are going to travel, the players are going to the national teams and it’s difficult after to control it, so I think something is going to rise unfortunately.
"I would love to say or to guess it's not going to happen but from experience it happened in two or three waves already worldwide, so if you move you take a risk to be contaminated, to get the virus again."
Earlier this month, FIFA granted clubs the right to refuse to release players called up to their national teams if there is a mandatory quarantine period of five days or more on their return.
For Premier League clubs - and significantly for City given the make-up of Guardiola's squad - this means players representing Portugal or South American nations can be held back because anyone returning from those countries will need to quarantine in a hotel for 10 days as they are on the UK's "red list".
Guardiola said there had been no discussions between clubs and federations to his knowledge and does not want the Premier League's handling of the pandemic to be undermined.
"I think the Premier League should be concerned about this, all the leagues [should be] concerned," he said.
"I know the national federations need to play, for the qualification, for the friendly games, for their preparation for the European Championship in summer time, this is normal.
"But the reason why there were a lot of cases in the Premier League and now there is no cases is because people don't move - home and training centre, game, home no more than this.
"The players are going to the national team, they know the situation. We'll tell them to be careful and after they go to the national team they are going to protect them as well."
City will try to extend a record-breaking run of 16 consecutive victories at Goodison Park. They will be without in-form midfielder Ilkay Gundogan (groin), although Kevin De Bruyne (hamstring) will travel with the squad after a month on the sidelines.
After the initial Everton postponement, Guardiola did not envisage City - or any other side - being able to put such a relentless run together.
"That’s true, everyone thought [the season] would be cancelled again," he added.
"Here in England in December and January, the cases rose amazingly but the Premier League and all the clubs, all the team managers and the protocols were so effective."