The 24-year-old Dutch centre-back has been linked with a move away from the Bhoys this summer, with Everton reportedly keen on his services.
According to The Scottish Sun, the Premier League outfit are set to make a bid for the defender after watching him in action against Qarabag in the first leg of the Champions League third qualifying round at Celtic Park on Wednesday.
Deila is fully aware of the speculation surrounding one of his star players, but he has insisted that Van Dijk is committed to the team.
“Is Virgil calm over his situation? Yes, you can see that,” the Norwegian told The Scottish Sun. “We have good communication over these things.
“These games are important for him and also for us. I was very happy with him.”
Should Virgil van Dijk leave Celtic?
Van Dijk is one of the best players in the current Celtic squad, and losing him would be a blow for the Hoops if they qualify for the group stage of the Champions League.
Celtic are likely to dominate Scottish football and win the Scottish Premiership without the former Groningen star, but they need him for the Champions League.
If the Bhoys make it through to the group stage of Europe’s premier club competition, then Van Dijk should remain at Celtic as he is not going to play in the Champions League anytime soon if he moves to Everton this summer.