Washed and dried blood stains...

So, my boyfriend gave plasma about 2 weeks ago. When the nurse took the needle thingy out he bled all over his sweat pants. Normally this wouldn't be a big deal. He'd just take it to me and I'd get the stain out for him. But, being the 'busy bee' he is, he just threw the sweatpants in the washer A DAY LAYER. He also dried then, assuming it would come out. It faded a little but in no way did it come out. I can handle set in stains, but 2 week old, washed and dried blood stains are the devil. The only reason I'm even attempting to get the stain out is because they're his senior sweats and he adores them. I'm really trying to avoid bleaching them too because they're a 'comfortable grainy gray' that he can never find anywhere else. So calling all experienced ladies. I need your advice. 🙏🏼🙏🏼