70-300L focus ring rattle

I got a 70-300L upgrade from the same but non-L version; it's giving me pretty much what I wanted, much sharper IQ, better colour saturation etc.. but I noticed the focus ring rattles; it's smooth to turn but if I just tap it it moves around a bit - the entire white focus section that is.

Struggling to find much on this online; other than a couple of brief mentions... Is this normal? It happens on the non-L version too (which isn't exactly setting standards for quality) but just seems more noticible and substantial than other lenses.

Thanks