The right-back has signed a four-year contract after joining the club for a reported £6million fee.

Sugawara initially joined AZ on loan in 2019, before making the move permanent the next season.

In five years at the Dutch club, the Japan international made 198 appearances in all competitions, including a club-record 53 in Europe.

Speaking to the club's media channels, he said: "To come to Southampton and to play in the Premier League is one of my biggest dreams since I was young, so I am really excited to be here.

"I felt Southampton is a really good club. When Southampton gave me an offer, I said yes after one second!"

Sugawara is the sixth addition to Southampton's squad in this transfer window off the back of its return to the Premier League.