Lets think logically. Possible positions where Riyad can bat.
#3: He dont have the courage to bat at #3
#4: This is a good place for him. Once we were craving for a #4 batsman. He never took the position despite offered to take the position several times.To me Naeem is perfect for #4.So no to Riyad for #4.
#5: Taken by Shakib.
#6: Best candidate for this position is Nasir. As Nasir is still very inexperienced then best candidate here is Mushy.
#7: Taken by Nasir.
#8: Only position left for Riyad.
So i dont see any upper position left for Riyad.Only option can be if we promote all batsman 1 up but putting Naeem at #3 will be risky now.