Pieter Huistra believes Virgil van Dijk is ready to take the next step and join a bigger club than Celtic.

Huistra was van Dijk's boss at FC Groningen before the 23-year old left to join the Hoops in Glasgow in 2013.

Since then, van Dijk has emerged on the radars of the likes of Arsenal, Manchester United, Tottenham and Southampton and Huistra now feels he is prepared to move on.

The former Rangers winger is aware that Celtic boss Ronny Deila wants van Dijk to stay at Parkhead for one more season before he leaves but Huistra has implored him to go if there is real interest from the Premier League.

"Of course Ronny will want Virgil to stay at Celtic," he told The Express.

"But I don't agree that you stay for one more year at Celtic and then the really big clubs come for you.

"Until you make that next step up the ladder, you don't know where your career can take you.

"I know Virgil loves Celtic and is happy in Glasgow. That means he is in a good position.

"He's not at a club where he has a problem and must find a way out.

"But, if a club with ambition comes in, it will be hard to say 'no'.

"That's his decision and Celtic can only hope he does not get the chance to make this decision."