Van Dijk has been linked with a number of English clubs, with the Daily Telegraph suggesting that the Dutchman is a target for Sunderland, who narrowly avoided relegation last season.
However, the Scot has urged caution over any move away from the Bhoys if it’s something that van Dijk has started to seriously consider.
“He could be. I don’t want to be disrespectful – but it’s a big move from being a Scottish Premiership centre half to being a Premier League centre half,” he told talkSPORT.
Van Dijk has bags of potential
Regardless of Graham’s concerns over the differences between top flight Scottish and English football, it can’t hide the fact that van Dijk is a very good defender.
He reads the game well, he’s good in the air and he’s got a great burst of speed over the first five to ten yards.
He warrants a big transfer fee because he has the potential to develop further and could become a truly special player if he copes well at a supposedly higher standard.
The worry for Ronny Deila
What Celtic manager Ronny Deila will want to avoid is having an unmotivated player in his squad.
That could have negative knock on effects and could impact on the rest of the squad who may sense a negative mood, which works against the team.
If Celtic are going to progress on the domestic double they secured last season, they need everyone pulling in the right direction and thinking about nothing else other than the Bhoys.