Van Gaal is aware of Hiddink 's unbeaten record .
Van Gaal admits that while it will be no easy task his players are optimistic they will be able to kickstart their campaign with a win on Sunday .
Van Gaal is aware of Hiddink 's unbeaten record but admits that while it will be no easy task his players are optimistic they will be able to kickstart their campaign with a win on Sunday .