The Foxes went into the international break on the back of a 1-0 victory over Bournemouth, their first in the current top-flight campaign and one that lifted them up to 15th place in the Premier League table.
Danish defender Jannik Vestergaard could not take part in that fixture due to an ankle issue, but the towering centre-back turned out for his country this month and has been given the green light to return to domestic action here.
As a result, Leicester's only absentees for the trip south will be ankle victims Patson Daka and Jakub Stolarczyk, as well as Hamza Choudhury, who dislocated his shoulder in training at the start of the month.
Scorer of a hat-trick in the unforgettable 9-0 obliteration of 2019, Jamie Vardy has been involved in 12 league goals against Southampton down the years, eight of his own and four assists, his best record against a single opponent.
The 37-year-old should operate at the tip of an attacking quartet also housing Jordan Ayew, Stephy Mavididi and last weekend's match-winner Facundo Buonanotte, even though Abdul Fatawu struck a hat-trick in the 5-0 Championship win over Southampton in April.
Cooper also has no need to swap out either Oliver Skipp or Wilfred Ndidi in the middle, and the same goes for the defensive quartet of James Justin, Caleb Okoli, Wout Faes and Victor Kristiansen in front of Mads Hermansen.
Leicester City possible starting lineup:
Hermansen; Justin, Okoli, Faes, Kristiansen; Ndidi, Skipp; Ayew, Buonanotte, Mavididi; Vardy