Portuguese Air Force aircrafts fly over a national flag during a ceremony marking Portugal Day, the national day of Portugal, at the Jeronimos Monastery in Lisbon, Portugal, June 10, 2020. The day was marked all over the country in a serene emotional atmosphere as some citizens are still mourning the loss of loved ones to COVID-19 while looking into the future with optimism about return to "normal life." (Photo by Pedro Fiuza/Xinhua)

Nearly four months after it was suspended, UEFA's plans to complete the Champions League in Portugal are once again under threat from the coronavirus, even if the organizers themselves insist there is "no Plan B."

UEFA President Aleksander Ceferin claimed that following a meeting with Portuguese Prime Minister Antonio Costa that there was no need to make alternative arrangements to the planned "final eight" straight knockout format for the quarterfinals onwards, with all games set to take place in Lisbon.

Costa himself said that "all measures are being taken to ensure that we will host this tournament in a safe and secure manner."

However, the ongoing health situation in Portugal casts some doubt on those pronouncements.

On Wednesday, lockdown restrictions were reimposed on 19 neighborhoods across the northern periphery of Lisbon where COVID-19 outbreaks persist. 

The restrictions concern some 700,000 people and will remain in place for at least two weeks.

With an average of 321 per day, the number of new cases being recorded in Portugal grew by a third in June ­compared to the previous month.

The majority of new cases are in the Lisbon area, and it is the capital which is due to host the latter stages of the Champions League, starting with the quarterfinal on August 12 and concluding with the final on August 23.

Alarm bells may be ringing within European football's governing body, especially as the Champions League was suspended in March and remains frozen in the last-16 stage, which has not been completed.

Costa has done his best to reassure Ceferin and insisted in an interview with Spanish daily La Vanguardia that the lockdown measures "do not concern the centre of Lisbon, where the Champions League will be staged."

However, the locked down neighborhood of Santa Clara borders that of Lumiar, the area in which the Estadio Jose Alvalade is situated. 

The home of Sporting Lisbon is scheduled to share hosting of the Champions League matches with Benfica's nearby Estadio da Luz.