Southampton have signed AZ Alkmaar defender Yukinari Sugawara on a four-year deal.
Southampton have bolstered their defence by signing centre-back Nathan Wood from Swansea.
Former Chelsea, Southampton, and England defender Ryan Bertrand has announced his retirement from football, after 18 years in the game.
Southampton will play in the Premier League again after just one season away following their 1-0 victory over Leeds United in the play-off final at Wembley, courtesy of an Adam Armstrong goal.
Jason Wilcox has left Southampton to become Manchester United's new technical director with immediate effect.
Nigerian international Paul Onuachu has declared that he and his family want to remain in Trabzon despite a proposed return to Southampton.