New drain post/question

I apologize in advance for repeating this question. I wasn't sure how to upload a pic via a reply to the original posting. That said, PLEASE SEE IMAGE BELOW for clarification of my question and thanks for understanding.

In a concrete floor, I have roughed in a 2" riser for a shower drain. However, I believe I may have made the following mistake.

When I roughed in the trap and riser, I did NOT leave a space around the 2" riser. In other words, the concrete I poured is up to and around the riser. The 2" PVC riser sticks up about 3" from the floor.

In order to attach an 828 series Sioux Chief drain, it looks like I need to chisel concrete out from around the riser to push the drain and gasket around the riser and down into the slab.

The "height" of the Sioux Chief drain is 2", and from the concrete slab floor to the shower floor through the drain opening is about 1".

I thought it protocol to leave the riser about 2" up from the floor when roughing in, but now I'm confused. The drain body and locknut look like they would raise the shower floor when attached and pushed down over the riser.

Is there a specific drain or way to seal around the riser and drain to make this work without having to break out the concrete around the riser?

Thanks for assistance and clarification on drain installation.

Just knock out enough concrete so the drain can be fitted to the pan.

Normally we block out to give enough space for the drain to recess into the floor.

Well your suppose to get that p-trap perfect before pouring that concrete so that when you go to put the shower in, it fits like a glove. Normally we would use a tub box to hold that drain area under the shower clear and so you can adjust the height and fit your shower flange correctly.