John Thorrington, a 17-year-old midfielder from Palos Verdes, Calif., has signed a two-year professional contract with Premier League champion Manchester United. Thorrington, who holds a British passport due to his father’s British background, becomes the youngest U.S. player to sign a pro contract in England. Jovan Kirovski joined Manchester United’s youth team at the age of 16 and worked his way up to the reserve team, but was unable to obtain a work permit and sign a professional contract. Thorrington is expected to see action with the Manchester United reserves later this year.