United players have been training at Carrington, with manager Ruben Amorim putting his first-team players and youth academy talent through their paces. This is Amorim's first season in charge, and he is working to strengthen the team's defense, which conceded 54 goals in the Premier League last season.

Diego Leon has signed a long-term contract with United and has been given the number 30 shirt. He has already started training with the first team and will be looking to make a positive impact this season. United has no plans to send the 18-year-old on loan, and instead, he will be integrated into the team to help improve the defense.

Leon previously played for Cerro Porteno, where he wore the number 37 shirt, and for Paraguay's Under-20 national team, where he wore the number 4. He will be facing his first big test in a preseason clash against Leeds United, who have returned to the Premier League.