The Catalan club secured the championship with a 2-0 win over local rivals Espanyol on Thursday (15.05.25) and the coach has been amazed by the special bond that exists amongst the players.
Flick said: "This is, for me, the most important thing. You feel like a family, it's fantastic. Everyone in this club has his job and he's doing great with a lot of passion, with a really good attitude and mentality.
"Everyone knows how important this is for this club, for this team, and this helps me a lot to reach our goals."
The German manager added: "And of course, the players, the atmosphere in the dressing room. This is so great. I never had this before, it's really fantastic to see this.
"Everyone takes care of each other, and it's really good to see. So this is maybe in a small sentence, I think it's unique."
Teenage winger Lamine Yamal once again starred for Barca as he opened the scoring with a wonderful goal and Flick thinks that the 17-year-old ace has the "potential" to keep improving.
He said: "He's a really clever player, he's 17 years old now and really measured about a lot of things.
"And of course, you can see in every training, he has some special moments, and when you see this, it's unbelievable and good to see this.
"But at the end, I think also he has potential to improve and he has to do that. He has to train, to work hard the same like the other players."
Flick said that his players did not celebrate the title win on the pitch out of "respect" for Espanyol - after ugly scenes occurred when Barca won the title at the same stadium in 2023 - but revealed that they were able to enjoy their success in the dressing room instead.
He explained: "On the pitch, it was clear that we cannot celebrate there. It's normal, I think, was it two years ago? I don't want to have this, so it's all about the respect for the fans here.
"Of course, we celebrate in the dressing room, it was great, fantastic. All the players can do that."