Lucas Bergvall has concussion so is unavailable, but Frank praised his medical team for dealing with it well despite it being "a tricky situation" at the time.
Mohammed Kudus and Djed Spence both picked up knocks but could still be in contention for Tuesday's game.
On the behaviour of Micky van de Ven and Djed Spence after Saturday's game: "Micky and Djed came into my office yesterday and just said they wanted to say sorry for the situation. They didn't want it to look bad or disrespectful - any misconception that you can get in this beautiful media world. They were just frustrated with the performance from the loss and the booing during the game."
He said the boos were "more than fair" after the final whistle because it was another home defeat, but added: "During the game, we need the fans."
On facing Danish opponents: "I follow the results and the league as I still have good friends and colleagues working at different clubs. They are not in the best place but they are a very good team. I expect it to be a difficult game."
More on Copenhagen: "No matter if a team are in or out of form, the next game is when everything can change so we prepare like normal. We are very aware of their strengths and areas we might want to exploit. I expect a tough tactical challenge."