If you're gonna drop Fakhar and put Abdullah in his place, you pretty much have to do it either for the SL game or the Australia game. You don't want to play Abdullah in place of Fakhar for the India game (too much pressure for Abdullah to come in for your first WC match). I think worst case scenario, Fakhar gets a chance vs SL and then potentially a final chance vs India to really come to a definitive conclusion of whether he should switch out for Abdullah moving forward from that point.