Collins admitted: “It will probably be harder to keep him if we don’t qualify.
“For me, the biggest competition in the world is the Champions League. That’s where every player wants to play, every coach wants to coach and every supporter wants to be.
“It’s the biggest and best. You are up against the best players and coaches in the world. It’s exciting for everyone involved.
“If you are a centre-half playing in the Champions League you are up against the best forwards in the world. It’s a great challenge and if you do well in the Champions League it puts you on a different level.
“People look at you in a different light if you are taking care of top-class strikers. There is also the financial part of the story, of course.”In addition to trying to hold on to Van Dijk, Celtic are hopeful of making further additions to their squad before the transfer window closes at the end of next month.
Collins dismissed reports in the Dutch media linking them with Den Haag striker Michiel Kramer – “close, but wrong country” was his response to those claims.He added: “We have a good healthy squad right now. But, like every manager or coach will tell you, it can always get better.
“You always look at players to improve each department. It’s not easy.