Chelsea were keen on Southampton defender Virgil van Dijk before he moved to Celtic.

Former Aston Villa scout Arthur Numan says he watched Van Dijk when he was at Groningen and was aware that Chelsea were also keen at the time.

Numan, speaking with Metro Nieuws, was asked if Van Dijk could be likened to former Manchester United defender Jaap Stam.

"The parallel is there, but the comparison between Stam and Van Dijk is flawed," the former fullback said. "At PSV, Jaap was right away a rock.

"Jaap moved to United after the World Cup of 1998 where we were fourth. Oranje was of a slightly higher level than now. And with Jaap he was a Dutch champion with PSV, he played Champions League and in 1997 Jaap was voted footballer of the year. In short: he had already proven himself at the top, something Virgil has still to do."