Martin Caceres could make his Southampton debut against Manchester United in the EFL Cup final.
The Daily Echo says that Saints will sign the former Juventus and Barcelona centre-back once a work permit has been granted and other formalities are concluded.
However, the completion of the 29-year-old free agent's deal is expected to come too late for him to be involved in Saturday's Premier League match at Sunderland.
That means the next opportunity to deploy their new man, after the trip to the Stadium of Light, is in the League Cup final against Manchester United at Wembley.
Consequently, Caceres' first appearance will likely come at the national arena, as Saints aim for their first major silverware in 41 years.