The teams already qualified for the quarter-finals are Paris Saint-Germain, Atalanta, RB Leipzig and Atletico Madrid.
The unprecedented solution also sees the Ataturk Olympic Stadium in Istanbul - the originally scheduled host for the final - pushed back by one year.
The matches, Inter Milan vs Getafe and Sevilla vs Roma matches, whose first leg was also postponed, will be played as a single leg at a venue to be confirmed.
And on Wednesday UEFA confirmed their schedule to finish this year's European competitions.
Although not announced yet, the date for the draw is expected to take place in early August.
"The remaining round of 16 second leg matches will be played on the 7th and 8th of August, depending on the decision if they will be played in the home stadiums or Portugal".
34 fresh Covid-19 cases, one death in Uttarakhand
An additional 423 cases have been added to the recovery column, a figure which significantly outpaces new active cases. Manipur: The northeastern state has recorded 449 cases of the coronavirus disease and 91 people have recovered.
The Europa League last stage will be played as a final eight straight knock-out tournament in Cologne, Duisburg, Düsseldorf and Gelsenkirchen between August 10 and 21.
Sources have told ESPN that the close proximity of Lisbon's two stadiums - both built to host games at Euro 2004 - and ease of travel within a city with a high number of hotels make it well-equipped to accommodate eight squads and stage this summer's mini-tournament.
One-leg quarter- and semi-finals and the final will be played in the Portuguese capital from 12-23 August.
The remaining four matches in the round of 16 will be played August 7-8, either at home stadiums or in Portugal, depending on whether local restrictions on sporting events have been lifted.
In the Europa League, only six of eight first-leg games in the round of 16 were played. "It would be incompetent from us if we were to decide in advance about the situation".
Sources have told ESPN that Istanbul, which was due to host the Champions League final for the first time since 2005, had expressed reservations last month about staging the game because of the pandemic, which has led to ongoing restrictions of worldwide travel into Turkey.