While Benfica clinched the Primeira Liga title last season, the Saints finished six points adrift at the foot of the Premier League table.
Match preview
Benfica suffered only three defeats in 34 matches on their way to securing the Portuguese top-flight title last term, scoring a whopping 82 goals while conceding just 20 in the process.
Despite the best efforts of arch-rivals Porto - who pushed Benfica all the way to eventually finish two points behind Roger Schmidt's side - the Eagles stood firm and claimed their first Primeira Liga title since 2018-19.
It is also worth remembering that Benfica enjoyed a run to the quarter-finals of the Champions League last season, avoiding defeat against Paris Saint-German, Juventus and Maccabi Haifa to qualify for the knockout phase as Group H winners.
After notching a giant 7-1 aggregate victory over Club Brugge in the last 16, Schmidt's men fell to eventual finalists Inter Milan in the quarter-finals, suffering a 5-3 aggregate defeat.
Across all competitions last term, the Portuguese champions lost just four of their 51 matches after 90 minutes, so they will back themselves to kick-start their preparations for 2023-24 with a positive result on Wednesday.
In contrast, Southampton endured a 2022-23 campaign to forget, losing 25 of their 38 Premier League games to suffer relegation to the Championship following an 11-year stay in the top flight.
Ralph Hasenhuttl paid the price for the team's poor performances when he was sacked in November, with Nathan Jones coming in as his successor, but the former Luton Town boss only lasted until February.
Ex-Valencia Under-18 manager Ruben Selles was handed the seemingly impossible job of keeping the Saints in the Premier League, but the Spaniard ultimately failed to save the club from relegation.
Having made a name for himself at MK Dons and Swansea City, Russell Martin has been tasked with leading Southampton's promotion bid in 2023-24, as the 37-year-old signed a three-year contract last month.
Although Wednesday's clash with Benfica will likely be a baptism of fire for Martin, the new manager will be eager to give players minutes on the pitch and learn as much as possible about his squad.
Benfica friendly form:
Benfica form (all competitions):
W
W
W
W
D
W
Southampton friendly form:
Southampton form (all competitions):
L
L
L
L
L
D
Team News
Benfica's teenage stopper Andre Gomes remains sidelined due to injury, meaning that Odysseas Vlachodimos and Samuel Soares could share the goalkeeping responsibilities on Wednesday.
The Eagles have already made a couple of high-profile acquisitions this summer, with Angel Di Maria arriving on a free transfer and Orkun Kokcu joining from Feyenoord, so the new arrivals could get feature at St George's Park.
Southampton's injury list contains Spanish teenager Juan Larios, who made just five Premier League appearances last season before missing the remainder of the campaign.
Theo Walcott and Mohamed Elyounoussi have left the Saints after their contracts expired, while Willy Caballero has retired, although no fresh faces have arrived at St Mary's so far this summer.
With question marks over the future of key players such as James Ward-Prowse, Romeo Lavia, Kyle Walker-Peters and Tino Livramento, Russell Martin could field an experimental side as he takes charge of his first match.
Benfica possible starting lineup:
Vlachodimos; Gilberto, Silva, Otamendi, Grimaldo; Luis, Chiquinho; Mario, Silva, Aursnes; Ramos
Southampton possible starting lineup:
McCarthy; Bree, Bednarek, Lyanco, Walker-Peters; Ward-Prowse, Lavia; Armstrong, Alcaraz, Aribo; Sulemana
We say: Benfica 3-1 Southampton
Pre-season friendlies often produce shock results, but the Portuguese champions should have more than enough quality to overcome Southampton, who are preparing for life in the second tier of English football.