Lie Him on tummy on floor and put a fav toy beside him but far enough away he can't grab it without moving.

Some children do not roll as they sit and then crawl but I am concerned that he is not doing any of this. Has your MCHN done a Brigance test?? this is a secondary test that can be used to determine issues if concerns raised on PEDS (booklet you fill out at each appt)

I also do not think he is crying to get picked up, leaving him longer wont make him do things as he will just get more upset.

Good luck