Southampton monitoring Indi
The Holland international played under St Mary’s boss Ronald Koeman at Feynoord until both left the club last summer.
And Southampton scouts have been watching the 22-year-old throughout his first few months in Portuguese football.
Martins Indi can play at left-back or centre-half and was a regular starter in the Dutch team that finished third at last summer’s World Cup.
Southampton could wait until the end of the season before making a move.