Saints have taken 19 year old Ussumane Djaló on loan from Portuguese side FC Porto to play in the Academy side subject to a work permit.
Djaló started his career with Benfica before joining Porto and playing for their B Team in Portugal's second division and the UEFA Youth League.
Now he arrives at Southampton who will take a look at the player in the next few months, before deciding whether to take matters further and speak about doing a permanent deal in the summer.
Academy Director, Andy Goldie, said:
"We look forward to supporting Ussumane's development within the Under-21s programme over the remainder of the season, having been impressed with his progress at club and international level.
"He's an interesting prospect who strengthens our pathway in midfield and provides much-needed competition in our Under-21s group."