Pieter Huistra believes the Celtic Football Club and Scottish football in general has been brilliant for Virgil van Dijk.
The 23-year old Dutch centre-back has attracted the attention of many clubs in the English Premier League since he arrived in Glasgow from FC Groningen for £2.6million in the summer of 2013.
Van Dijk's former Groningen manager Huistra, who played as a winger for Rangers between 1990 and 1995, believes the move to Scotland has improved the player so much that he is now on the verge of making the step up to the big leagues.
"Celtic have been good for him and I know from my time in Scotland just how special it is to play for a club like this. It was the same for me at Rangers," Huistra told The Express.
"Celtic and Rangers are institutions and no one should underestimate how good it is to play with them and win trophies.
"But there comes a time when moving is an option. That's something for Virgil and his agent to investigate this summer."