Manchester United manager Sir Alex Ferguson says Arsenal are playing hardball over the sale of star striker Robin van Persie but he remains hopeful of luring the Dutchman to Old Trafford.

Ferguson says Arsenal are negotiating with other clubs about van Persie, with a perceived preference of selling to a non-English club but he says “we just have to persevere, hopefully it will come our way.”

He added “We’re not getting any breakthrough with Arsenal. It’s difficult to say why they’re operating this way.”

United have lost out in their bid to sign Brazilian Lucas Moura, who is bound for big-spending Paris Saint Germain.

Ferguson says the reported transfer fee of 45 million euros ($A53 million) for a 19-year-old shows “the game’s gone mad.”