London, Feb 28 : Manchester United football team manager Louis van Gaal believes that the club has not challenged for the Premier League title because they are short of a 20-goal-a-season striker.

United's top Premier League scorer this season is Robin van Persie with 10, while in contrast, Diego Costa and Sergio Aguero have scored 17 each for Chelsea and Manchester City respectively.

Van Gaal said that it is true, adding that Van Persie cannot deny it, Radamel Falcao cannot deny it and Wayne Rooney is not playing there much anymore, the BBC reported.

The Dutchman has come under criticised for playing striker Rooney in a deeper position, while Falcao has had limited opportunities, with Van Gaal questioning the Colombian's fitness.

Van Gaal said that at this moment, they don't have a striker who scores 20 goals.

United would face Sunderland on Saturday at the Old Trafford, having slipped to fourth in the table following last week's defeat to Swansea City.

The result left them 13 points behind Chelsea and five adrift of City, who have both scored 56 goals overall, compared to United's 44, the report added. (ANI)