Under the plan the competition, which was suspended in March due to the coronavirus pandemic, will resume with the second-leg of remaining last 16 games played at the scheduled venues.
The single leg quarter-final games will be played in Lisbon on four straight days from August 12-15.
The semi-finals will take place on August 18 and 19 and the final on August 23 in the Portuguese capital.
The plan allows for a quicker completion of the season than the traditional two-legged home and away format but does mean the competition will have six fewer games which will cost UEFA broadcast revenue.
Spains Atletico Madrid and Italys Atlanta already qualified
The games are likely to be shared between Lisbon's two major stadiums - Benfica's Estadio da Luz and Sporting Lisbon's Jose Alvalade stadium.
Organisers are proceeding on the basis that matches will be played behind closed-doors but UEFA is understood to have left the door open for possible changes should public health conditions in Portugal allow.
The teams already qualified for the quarter-finals are France's Paris St Germain, Italy's Atalanta, Spain's Atletico Madrid and Germany's RB Leipzig.
The remaining last 16 second-leg fixtures are Manchester City's home leg against Real Madrid, Chelsea's trip to Bayern Munich, Juventus's home game against Olympique Lyonnais and Napoli's visit to Barcelona.
Istanbul was due to host the 2020 final but will now, instead be the venue for the 2021 edition, with all other scheduled hosts moving back a year.
A similar format will be used to decide the Europa League competition at German venues from August 10.
The remaining last 16 games will be held at neutral venues in Germany with the 'Final Eight' held in Duisburg, Duesseldorf, Gelsenkirchen and Cologne.
Manchester United, AS Roma and Inter Milan are among the teams still involved in the Europa League.
The traditional opener to the European season, the UEFA Super Cup, is expected to be held in Budapest on September 24.