Ronald Koeman says the form of Virgil van Dijk has helped turned Southampton into European contenders in the Premier League.
The Netherlands international was signed by Koeman from Celtic in September and has made 30 appearances in all competitions, scoring three goals.
His central defensive partnership with Jose Fonte has been instrumental in Southampton's rise up the table under Koeman, earning the 24-year-old high praise from his Dutch coach.
"He is strong, he's fast and he's important in the way we like to build-up [from the back]," Koeman told Sky Sports.
"He is good at short passing, he has a good long pass and he has got a good partnership with Jose Fonte and last Saturday he was good in tandem with Ryan Bertrand.
"He is also a good header of the ball, has a good shot and is a good free-kick taker. He's a very good centre-back."