Amir Khan has admitted he is taking a risk by fighting undefeated Colombian Breidis Prescott. Commonwealth lightweight champion Khan has been accused of avoiding big punchers in the past, but Prescott is likely to provide the sternest test of his career. The 25-year-old, who has won all of his 19 fights with 17 knockouts, is bigger than Khan and has a longer reach. Speaking ahead of the clash at the MEN Arena in Manchester on Saturday night, Khan said: "It is risky. I am a fighter who likes to take risks in boxing. "It is a big step for me, fighting an opponent with a good knockout percentage. "It is a 50-50 fight. It is going to be a tough fight on the night. The best man is going to win the fight." The bout will be Khan's first with new trainer Jorge Rubio in his corner, and the Cuban is expected to increase the Bolton fighter's already impressive hand speed.