UEFA president Aleksander Ceferin has eased fears the Champions League could come under threat by further coronavirus outbreaks.
The current continental campaign will conclude in Portugal in August after being halted by the pandemic in March.
But from Wednesday, 19 neighbourhoods north of Lisbon, the host city, will go back into lockdown, with gatherings limited to five people.
Portuguese prime minister Antonio Costa spoke to Ceferin and Portuguese Football Federation president Fernando Gomes via video on Tuesday ahead of the mini-tournament in August.
Ceferin said in a statement: "I would like to thank the Portuguese prime minister Antonio Costa for his dedication to this project and the work he is doing alongside the Portuguese Football Federation to ensure that Portugal delivers a successful tournament.
"I am confident that with the continued and constant collaboration between all stakeholders, we will conclude the season in a positive way in Lisbon. There is no need for a Plan B."
The final-eight event is due to begin with the first quarter-final on 12 August, with the final scheduled for August 23.
Manchester City lead Real Madrid 2-1 from their first leg while Chelsea trail Bayern Munich 3-0 having seen the second legs of their last 16 matches postponed in March.
No venues have been confirmed for the outstanding last-16 games but they are due to be played on 7 and 8 August.
Ties from the quarter-finals onwards will be split between Benfica's Stadium of Light and Sporting Lisbon's Estadio Jose Alvalade.