Cédric Soares is about to become Ronald Koeman's second acquisition of the summer, following in the footsteps of Spanish international forward Juanmi.
Juanmi joined Saints earlier this week, putting pen-to-paper on a four-year deal on Tuesday evening that saw the completion of a €7m switch from La Liga side Málaga.
Cédric, a 23-year-old right-back, is now expected to do the same before the week has ended.
The Sporting Lisbon defender will make the move to the south coast for a fee in the region of €5m.
It is understood that Cédric is in England and the deal will complete on Thursday, after the player has passed his medical assessment.
The fee is lower than expected by some quarters, but the fact that the players has only 12 months of contract remaining at the Lisbon club has been a considerable factor in negotiations between the two clubs.
Stoke City were also interested in the German-born right-back, who has represented Portugal at every youth level from U16 to U21 - making a total of 72 appearances at youth international level.
He made his senior debut for Portugal in a 2-1 friendly defeat against France in October 2014, and currently has four caps for the senior squad, where he has played alongside Saints captain José Fonte.
His club career started with Sporting Lisbon, who he joined at the age of eight. Although he was born in Singen in Germany, he was born to two Portuguese parents and returned to his parents' home nation at the age of two.
In 2011, his debut for the first team came, with Cédric playing the full 90 minutes in a 1-0 loss to Vitória de Setúbal.
For the 2011-12 season, he was sent on loan to Académica de Coimbra, winning the Taça de Portugal - the Portuguese cup - with a 1-0 win over parent club Sporting Lisbon in the final.
During his loan spell with Académica de Coimbra, he made 29 first team appearances.
He has represented the Sporting Lisbon first team on 59 occasions, picking up silverware in the 2014-15 season as part of the side which won the Taça de Portugal - despite Cédric being sent-off after just 14 minutes of the final for conceding a penalty.
He played the second half of last night's 1-0 win over France for the Portuguese senior team, which saw him line up alongside Fonte, who has identified Cédric as the sort of signing Southampton should be making.
Speaking to the Portuguese media, Saints skipper Fonte said:
"I would like to have Cedric as a team-mate at Southampton.
"He is a great player and our club needs players of his level."
To discover more about Cédric, we spoke to Tom Kundert - a Portuguese football expert - to find out what Saints fans can expect from the hotly-anticipated second signing of the summer transfer window.
1) For those fans who have not watched him, is Cédric a more modern attacking wing back, like Saints current right back Nathaniel Clyne, or is he a more conservative full-back?
He's definitely a modern, attacking full-back. He is excellent at combination play in the attacking half and perhaps his stand-out skill is his superb crossing ability, even when space and time is at a premium.
2) What would you say are Cédric's biggest strengths and weaknesses?
His biggest strengths are his crossing and his ability to combine well with his midfielders in the attacking-third to engineer incisive attacking moves, whether on the counter or in continuous offence. His main weaknesses are a tendency to be caught out of position defensively at times, and he is not particularly strong in the tackle.
3) The rumoured price is around €7m; does that represent a better deal for Saints or Sporting?
It's not bad for Sporting at this moment, considering he's out of contract next season, but if he continues to develop well it will prove to be a sound investment for Saints. He is widely-expected to nail down the right-back spot for the Portuguese national team for years to come.
4) Southampton have also been rumoured to be watching Benfica's Andre Almeida, having had a big scouting presence in Portugal. Do you think this would be a good market for a club like Saints?
Yes, there is always good talent at affordable prices available in Portugal. Lack of money in the game in this country means that clubs tend to spend what little money is available on excellent coaching, but then teams are unable to keep the players they create, because they cannot compete on the wage front and they need transfer revenue.
5) Finally, if Saints do sign Cedric, there will be two Southampton players in the Portugal set-up, along with captain Jose Fonte. What would you say is the general opinion on Saints within Portugal?
Good solid club, much in the image of José Fonte himself!
St. Mary's Musings would like to thank Tom for talking to us for the purpose of the above piece.