The bag was sealed in the plastic wrapper when I received it directly from adidas, so this clearly happened in the factory whilst being made, and was sent to me regardless. I didn’t even realise it was blood until I went to use it, and was rubbing at the mark with my fingers trying to get it off. This is a huge hazard as could carry infectious diseases. It should never have left the factory, and I would expect much better quality control from a brand like adidas. Really disappointing.