The reigning champions played out a goalless stalemate with France at the weekend, while Sweden fell to a 2-1 defeat to Croatia on Sunday evening.
Portugal's defence of their Nations League crown continued with a 0-0 draw against fellow European heavyweights France on Sunday evening, with the reigning European champions still level on points with the current World Cup holders following that stalemate.
Fernando Santos has now witnessed his side share the spoils in a goalless draw twice in a row following their friendly bout with Spain last week, and Portugal have a serious fight on their hands if they are to secure qualification for the Nations League finals and retain their crown.
However, Portugal's recent record speaks for itself - the reigning Nations League and European champions have only tasted defeat in one of their last 20 matches in all competitions - a 2-1 defeat to Ukraine in the Euro 2020 qualifiers.
With France set to take on Croatia in a repeat of the 2018 World Cup final on the same evening, Santos will be hoping that the Chequered Ones can successfully seek revenge against Didier Deschamps's men and pick up all three points on Wednesday, which would see Portugal open up a three-point gap at the top of Group A3 should they prevail over Sweden.
Portugal will no doubt be feeling optimistic about their chances of victory in this encounter, with Sweden yet to get off the mark in the 2020-21 Nations League following three defeats from three.
Janne Andersson's men were always expected to struggle in a group with the European champions, World Cup holders and World Cup runners-up, and Sweden are very much at risk of a swift return to League B with three group stage matches remaining.
The Nordic nation had already lost to France and Portugal in the month of September, and Andersson's side are still awaiting their first point in the group after succumbing to a 2-1 defeat to Croatia on Sunday, with Nikola Vlasic and Andrej Kramaric netting either side of a Marcus Berg equaliser.
Sweden have only come out on top in one of their last 11 meetings with Portugal across all competitions, with the Nordic nation last beating the European champions 3-2 in a 2017 friendly.
Portugal Nations League form: WWD
Portugal form (all competitions): WWWWDD
Sweden Nations League form: LLL
Sweden form (all competitions): WWLLWL
Portugal were rocked by the news that Cristiano Ronaldo had tested positive for coronavirus, and the Juventus man is set to be replaced on the left-hand side by Liverpool's Diogo Jota, with all other players returning negative tests since the news broke.
Santos is expected to name another strong lineup amid a congested fixture schedule, but Premier League duo Joao Cancelo and Joao Moutinho are options for change should the Portugal manager look to freshen things up.
As far as Sweden are concerned, Ludwig Augustinsson has left the camp to rejoin Werder Bremen in preparation for the Bundesliga's resumption, while fellow defender Filip Helander is back at Rangers following an injury.
The visitors have also revealed that an unnamed goalkeeper in the squad has picked up a minor problem, and while none of the current three shot-stoppers has pulled out, Isak Pettersson has come in as a fourth option.
Portugal possible starting lineup:
Patricio; Cancelo, Pepe, Dias, Guerreiro; Pereira, Moutinho, Fernandes; B. Silva, Felix, Jota
Sweden possible starting lineup:
Olsen; Krafth, Lindelof, Jansson, M. Olsson; Kulusevski, Ekdal, K. Olsson, Forsberg; Isak, Berg
We say: Portugal 3-1 Sweden
Portugal and Sweden have endured contrasting starts to their Nations League campaigns and we can only see one clear winner in this match. The reigning Nations League champions will be determined to get back to winning ways against a Sweden side who are on a three-game losing streak in the competition, and even without the presence of the illustrious Ronaldo, we are backing the hosts to prevail in convincing fashion.