The unique competition between the Champions League last eight in August is likely to produce a surprise winner, according to Abel Xavier.

Former Portugal international Xavier is thrilled the country's capital city of Lisbon will host one-off matches from the quarter-final stage onwards as the competition ends with a mini-tournament.

Atalanta and RB Leipzig are among the teams already to have secured their place in the last eight, along with Paris Saint-Germain and Atletico Madrid.

Lyon and Napoli are hoping to upset Juventus and Barcelona respectively when the last-16 stage is concluded, while Bayern Munich and Manchester City – who lead their own ties – are rated as favourites to win the competition.

But Xavier feels the unique format and environment could benefit the sides who are not used to playing in the final stages.

"Yes, I think from my analysis of what I've seen with surprising results that have been happening in the [domestic] leagues, there is an extra buzz with the top teams because of the fans," Xavier said to Stats Perform News.

"There is a moment where fans give a buzz to the top teams. I think there is going to be a surprise in this last stage. 

"There are teams who are in the group and they can surprise because the teams are more exposed. 

"The teams who aren't used to being in this stage, they are more strong mentally because they play more freely, they play more open and the gap [in quality] will reduce, making games more competitive.

"For that reason, I honestly believe that it is going to be difficult and there will be a surprise in the end."

Xavier hopes the Champions League conclusion will be a fitting reward for those who have worked hardest during the coronavirus pandemic.

The former Liverpool defender added: "It's a completely different environment because of the pandemic situation and everybody readjusts. There is sporting reasons and also economic reasons.

"When you're looking at the leagues and what options they have to play and finish the leagues, there are a few countries that have decided to not continue playing, repeating the health issues.

"They for me are the priority - before football comes health. Of course, everyone must be protected and safe. 

"Portugal is one of the countries that has managed the [COVID-19] crisis very well. I think when you look at the impact, now things are becoming better, I think it's a safe place [to play football]. 

"For that reason, I believe that the opportunity to receive the eight best teams and play this kind of format in Lisbon is also a way to appreciate and say thanks for all those who made these events possible. 

"We are talking about people who work in health, hospitals because we are talking about health matters. If you are not safe you cannot have football either. 

"For that reason, I think Portugal, if things keep going the same way [with COVID-19], the teams will come here and it's going to be a great competition in a positive way.

"It's also going to attract a very positive image in Portugal because when you look back, Portugal was able to organise the big events in the best way possible. 

"For that reason, I think the final stages will be possible and I hope we can have a percentage of the public in the stadium, that would also be an upgrade if things [with COVID-19] stay like this with safety."