Both tournaments resume this week after five months due to the coronavirus pandemic.
The protocols were distributed to the 28 still offered in any of the competitions.
Both competitions end with the last 8 tournaments behind closed doors in Portugal and Germany.
The Champions League final will take place in Lisbon on 23 August, two days after the Europa League final in Cologne.
“UEFA expects all parties to adhere to the most productive hygiene practices, whether in controlled environments and privacy,” the protocols state.
“It is imperative that all the precautions set out in this document, as well as popular hygiene practices, be strictly respectable across all members of these other groups.
“Failure to comply with these social norms can have serious consequences for the organization of parties abroad.”
The return of the European interclub festival will be followed until the start of the league of Nations foreign qualifiers in early September.
In addition, the 2020–21 European club season begins on 8 August, with the NorthIrlands of Linfield worried in the opening circular of the Champions League.
The protocols themselves were drafted under the direction of UEFA Medical Committee Chairman Tim Meyer, who is also aware of Bundesliga protocols in Germany.
Players and club staff have been informed that they will be assessed two or 3 days before leaving their home country for the “last eight” tournaments and again, at the venue, the day before the match.
UEFA promises the effects “at least six hours” before the start of the match.
Clubs have been informed that their players should wear a mask “in all public places” when travelling and the use of charter flights “is highly recommended”.
Players were also reminded to change their jerseys.
UEFA has rejected requests from some clubs, including Manchester United, the Wolves and Inter Milan, to be allowed in and out of Germany for individual matches, there is more emphasis on the strict regulations surrounding the hotels in which individual clubs are housed.
Among those for this are: