“It was a reckless challenge,” Slot said. “I’ve said a lot about the tackle of Xavi Simons, which for me was completely unintentional. I don’t think you will ever get an injury out of a tackle like that.
“But the tackle of van de Ven, if you make a tackle like that 10 times, 10 times there is a serious chance the player gets a serious injury.”
Van de Ven, who has spoken to Isak since the incident, escaped punishment for the challenge, and Frank defended his player while praising his competitiveness.
“No, I'm obviously disagreeing,” Frank said. “In many ways, I think we are talking about a defender in Micky van de Ven that will do everything he can to avoid the goal, so it's a transition.
“He's sprinting back in, this ball slides down the side, and he does everything he can to see if he can block that shot, so he's sliding. Unfortunately, Isak's planted his foot straight there, and that makes it look worse than it is. I think that would be a natural reaction for any defender.
“I'll put it this way: if my defender doesn't do that, then I don't think they are true defenders.
“He's a very fair and competitive player. That's one thing. The other thing, you also know that the two players have sorted it out, so that's a good sign of how they've sorted it out. A good sign.”
Asked whether he thought Slot’s comments could change a referee’s perception of Van de Ven, Frank said it was not in the 24-year-old’s character to act maliciously.
“I hope not,” he continued. “I don't really understand the comment, but that's not for me to be too clever about.
“I just think if you look at that, there's not too much in it and it's the first time, as you said, so I don't think it will be a problem.”