United flew back to Manchester just hours after the final whistle at St Etienne in order to have more time to prepare for EFL Cup Final on Sunday.
Jose will be without Michael Carrick, Wayne Rooney and possibly even Henrikh Mkhitaryan who limped off with a hamstring injury shortly after scoring the winning goal in France.
“Honestly, I don’t think Mkhitaryan is fit for the final. I think him and Michael are both out,” said Mourinho.
For Southampton, Sofiane Boufal remains a doubt for the Final with an ankle injury, while Virgil van Dijk and Charlie Austin are ruled out.
The road to the Final at Wembley Stadium was a relatively easy one for Southampton even though they faced difficult opponents on paper. They beat Sunderland, Crystal Palace, Arsenal and Liverpool.
United never looked like losing as well, beating the likes of Northampton, Manchester City, West Ham United and Hull City in the process.
Manchester United will play in their home shirts while Southampton will wear their alternative 3rd kit which is predominately white.
Andre Marriner is the appointed referee for the EFL Cup Final.