Van Dijk joined the Saints from Scottish Premiership champions Celtic on a five-year contract in the summer transfer window.
Former Arsenal star Keown has stated that he was impressed by what he saw of Van Dijk during the Dutchman’s time at Celtic.
“I’ve seen flashes of Virgil van Dijk and he is an impressive defender,” the Englishman wrote in The Daily Mail.
“It shows the Dutch influence that the club is now able to tap into thanks to Ronald Koeman but what does his signing mean for Steven Caulker?”
Van Dijk was one of the best players for Celtic over the past two years and was arguably the best centre-back in the Scottish Premiership.
It will be interesting to see how the Dutchman does in the Premier League, especially as there will be pressure on him to hit the ground running at Southampton.