PVC drain through concrete slab

I'm running a 2" PVC drain pipe and would like it to pass through a concrete slab. The house is supported by pilings buried in the ground, so the slab is not structural. I've seen lots of mention that PVC piping passing through concrete needs a sleeve, but I think that's for when concrete is poured around the pipe and I don't plan on refilling the hole. So if I chisel a 3" hole for the 2" pipe, is that ok?