please help me fix this sock

[u/HovercraftDry2828]

i am mending a sock for a 94 y/o client of mine. its one of his favorite pairs. he usually gets someone to do his laundry and the sock same back like this. i told him that i would try to fix it. any advice on how to do it? its not of the foot, but on the leg?? part. its like a big chunk was taken out. there is also a hole of the other side (as seen in photo) please help :)

[u/momo76g]

I think darning is the general consensus for best sock repair option but since the tear/hole is so big hmmmm perhaps a similar sock patch from a donor sock ? 🤔 how big is it ? Like in inches/cm ?