French media had reported that the manager and player had a discussion after PSG's 3-1 win over Rennes on Friday, and that Dembele was omitted from the squad for Tuesday's game with Arsenal for disciplinary reasons.
While Luis Enrique said there was no argument between himself and Dembele, he took the decision for the good of the team.
"If someone doesn't comply with the requirements of the team, it means that they are not ready," Luis Enrique told a press conference.
"It means in such an important week, with such an important game coming up, we need every player to be fully available.
"My objective is to do the best for the team and that was my decision."
The manager was pressed further on making such an important choice, leaving out a player who has scored four league goals in six games, for such a key European game.
"You think it is easy to create a team. You press a button and the 11 best players play and everything goes well," the manager said.
"No, making a team takes a certain amount of circumstances that can be difficult. Yesterday I had to make a difficult decision but I think it is the best decision without any doubt.
"I would make it 100 more times. That doesn't mean the situation is irreversible. But the best situation for the team right now is this, in my opinion."
The coach would not give further details on what happened with Dembele, but said that his job is to create a team and that is what he will continue to do.
"I am not going to make a soap opera out of it, there was no argument between the player and me. There was a problem with the players responsibility to the team. Nothing else," he said.
"I signed for PSG last season to create a team. That is something I can guarantee. Until the last day that I am in Paris, I am going to make a team.
"A team that is brave, daring, plays good football or tries to. The first day I cannot do that I will go back home."
PSG won their opening Champions League game 1-0 against Girona while Arsenal were held to a 0-0 draw away to Atalanta.