Around the hour mark, Rangers defender Broadfoot slid in on Valencia, winning the ball cleanly in the process, with the Ecuadorian's left ankle appearing to get trapped between turf and the Scotland man's body as they each slid along the surface, resulting in the injury.
Valencia was visibly distressed and required oxygen as he was carefully carried off the pitch and down the tunnel. An ambulance was on stand-by at Old Trafford, ready to transport the former Wigan Athletic man straight to hospital.
The 25-year-old has had to wait for his chance thus far this term even after an excellent performance in the Community Shield victory over Chelsea, largely due to the impressive form of Portugal star Nani.
The injury, which is yet to be diagnosed but which similar instances have seen players ruled out for several months, will come as a huge blow to boss Sir Alex Ferguson, with the winger enjoying a fantastic debut season at Old Trafford last term as United finished second in the Premier League. (goal)
Video : Antonio Valencia Breaks His Leg !