Ings was taken off just before the hour mark of the Saints' 2-1 loss to Tottenham with a suspected thigh problem.
Southampton have had a nine-day rest between matches, but Ralph Hasenhuttl will not want to take any unnecessary risks when it comes to the England international's fitness.
Should Ings miss out, Nathan Redmond and Che Adams are likely to lead the line, with Theo Walcott and Stuart Armstrong the favourites to start in the two wide positions.
Walcott has scored five goals in his 10 Premier League appearances against Leicester, only netting more against Tottenham Hotspur and West Ham United in the competition (six each).
The prolonged break between games is good news for Ryan Bertrand, who should return to the side here in place of Mohammed Salisu.
Despite previously being ruled out for the season, Michael Obafemi has returned to training and may play a part on Friday, but William Smallbone and Oriol Romeu are definitely out.
Southampton possible starting lineup: McCarthy; Walker-Peters, Bednarek, Vestergaard, Bertrand; Armstrong, Diallo, Ward-Prowse, Walcott; Redmond, Adams
> Click here to see how Leicester could line up for this contest
Monaco 
Stade Brestois 29 
Bordeaux 
Nimes 
Bayern Munich 
FC Augsburg 
Paris Saint Germain 
Toulouse 
CSKA Moscow 
FC Rostov 
Leicester 
Chelsea 
Valencia 
Betis 
Dynamo Kyiv 
Chornomorets Odesa 
Verona 
Inter 
Bayer Leverkusen 
FC Heidenheim 
Borussia Dortmund 
SC Freiburg 
VFL Wolfsburg 
Union Berlin 
Arsenal 
Nottingham Forest 
Everton 
Brentford 
Spartak Moscow 
Lokomotiv Moscow 
Rangers 
Dundee Utd 
Atletico Madrid 
Alaves 
Lens 
Marseille 
Ingulets Petrove 
Shakhtar Donetsk 
AC Milan 
Juventus 
ST Malo 
Manchester City 
Tottenham 
Eintracht Frankfurt 
Werder Bremen 
Girona 
Espanyol 
Feyenoord 
Heerenveen 
ST Etienne 
Montpellier 
Grenoble Foot 38 
Heart Of Midlothian 
Celtic 
Reims 
Lyon 
PSV 
Groningen