Man United striker Wayne Rooney to miss 2-3 weeks after hurting knee in practice

Wayne Rooney, del Manchester United, se lamenta después de haber desperdiciado un tiro libre durante el partido de la Liga Premier de su equipo contra el Swansea, en el Liberty Stadium, en Swansea, Gales, el domingo 23 de diciembre de 2012. (AP foto/Jon Super) (The Associated Press)

Manchester United striker Wayne Rooney will miss up to three weeks with a knee injury.

Manager Alex Ferguson says he strained a ligament behind the knee when he tried to hit a volley late in practice Tuesday.

The England star missed United's 4-3 win over Newcastle on Wednesday. Ferguson didn't specify which knee was injured.