The 21-year-old has played an important role in Tito Vilanova's side during pre-season, making the most of the chances he has been given in the absence of Gerard Pique and Carles Puyol, who are still unavailable.
Speaking after Barca's 8-0 victory against Raja Casablanca on Saturday, Bartra stated that he is improving as a player in the club's first-team, and had special words of praise for Messi.
"Little by little, I am gaining trust, it is very important to get more playing time," he told Barca's website. "It is very good to play alongside Javier Mascherano and Daniel Alves. I learn a lot from them.
"It is great for any player from the Cantera to play alongside Messi. He makes everything easier. He is the best player in the world, there are no words to describe him.
"I have never seen a player as ambitious as him in the dressing room."