When Michael Carrick was asked about 15-year-old JJ Gabriel last month, he navigated the narrow path between high praise for a young player with immense talent and the knowledge he will ultimately be the one who decides when it is time for first-team exposure. "JJ is one of the boys," he said. Ryan Giggs, Manchester United's record appearance holder, was 17 years old when he made his club debut in 1991.