How can you remove a blood stain from a white cotton garment?
Dave, have you exposed the stain to hot water or to the hot dryer? If so, that stain may be baked into the cotton fibers. However, I’d try two things before giving up. One, an oxy-type cleaner. Two, an enzyme based cleaner like Biz, designed to break down organic matter. I don’t use oxy stuff myself, but I’d soak anything white in Biz without fear. (If there’s colored player numbers or lettering, don’t soak that part.) If either one lightened the stain at all, I’d then use an old toothbrush to scrub Zout (not Shout, but Zout) stain remover into the spot, going every direction on both sides of the fabric, before laundering normally. Beyond that, there’s always coating it with cornstarch as a cover-up!