Martin Caceres could make his debut for Southampton in the EFL Cup final against Manchester United as Saints bid for a first major trophy since 1976.
The 29-year-old former Barcelona and Juventus defender joined the club last week and impressed boss Claude Puel during a training camp in Spain.
United captain Wayne Rooney, who had been linked with a move to China, will be involved, said boss Jose Mourinho.
Mourinho is looking to add to the three League Cups he won at Chelsea.
Victory in Sunday's match at Wembley would mean the Portuguese wins a major trophy in his first season as United boss.