Southampton have completed their first signing since the appointment of Mauricio Pellegrino, with defender Jan Bednarek joining the Premier League club from Lech Poznan.
The 22-year-old has signed a five-year contract at Southampton, who also announced new deals for youngsters Sam Gallagher and Jack Stephens on the first day of the transfer window.
Poland Under-21 international Bednarek is focused on making the most on his opportunity at the Premier League club.
"I am so happy that I could join a club like Southampton," Bednarek said. "This is the moment I have worked for that makes my dreams come true. It only gives me motivation to work hard, to show my skills and to help Southampton to get better and better.
"I think it's a good step for me, because I have heard Southampton is such a good club for young players, so I can improve here. I think it will be a good move for me."
On a busy day at St Mary's, Southampton handed a five-year deal to 23-year-old defender Stephens, who ended the previous campaign deputising for the injured Van Dijk, while 21-year-old striker Gallagher penned a four-year contract after scoring 12 goals on loan for Blackburn Rovers last season.
And Pellegrino called for unity in his first interview since being appointed as Southampton's replacement for Claude Puel.
"For me, to be competitive, we need everybody," former Alaves coach Pellegrino told Southampton's website. "To make the people feel proud of the team we have to try to create this synergy between the players and the fans.
"We have to give them our effort, our passion, our work and they will feel this. If they feel this, I think it will be easier in the future. This is something the people quickly will feel when they see the players and the team is working together.
"This is something that is important, because when you are competing the small details make a huge difference."