The midfielder has attracted an approach from Manchester United over the past week.
However, after stepping in for the injured on Sunday for Barca's win against Real Oviedo, Casado has made it clear he is committed to the Blaugrana.
He said at the final whistle: "I am convinced that as long as I can wear this shirt and defend this badge, it will be my priority. It's a dream I've had since I was little, and I hope I can enjoy it much longer.
"I have confidence in myself and I know what I can bring to this team. I'm going to make the most of every minute I get. It's important to help the team when it's my turn."
Casado added: "Every minute I get to play in this shirt, I'm going to defend it to the death. The team played a good game. In the first half, we focused more on moving the opponent around.
"We knew that eventually they would tire and there would be gaps. In the second half, the pressure paid off."