Barbarez has accused former Nottingham Forest manager Cooper of deliberately dropping Bosnia midfielder Benjamin Tahirovic in recent games to leave him underdone for their World Cup playoff against Wales.
Brondby have denied the claims, while BBC Sport says Tahirovic has since apologised to his club coach.
Asked if he should do the same, Barbarez declared: "I don't think I should apologise for anything."
He continued: "The only important thing for me is that I trust my players, and the idea of all this was to create a puzzle for you so you can think about all these things," said Barbarez on Wednesday.
"I had the idea to protect the player. That's where all this talking was from.
"I've known Benjamin for the last two years, and I know what a good player he is and how he can be.
"So I think we should concentrate on tomorrow's match, which is the most important thing for both teams."