Please help urgent!!! Found my two year old Brahma rooster un able to move with a golf ball size lump on his back

[BigR00ster]

I came back home from a two week trip to find my rooster un able to move. After checking him I found a golf ball sized lump on his back with a gash through it and he seems to not be able to move one of his legs. He doesn't seem to be in any pain and will let me touch his legs without screaming. The day after I found him I found a possum under the coop which was promptly removed and taken to a forest farther away. He's been drinking water and a bit of food but not much, I've been putting chicken vitamins and electrolytes in his water to help him recover faster as well as putting blu kote on the wound.

 

[Yardmom]

A picture might help here. Is he eating and drinking on his own?

 

[Eggcessive]

Welcome to BYC. Pictures may help us see what you are seeing, including the wound and the legs. Is he able to reach his food and water? Is he eating any better? Chicken slings and chairs can help to get them up if they tolerate them, and can help with feeding. Here is a link for chickens sling chairs, and posts 5, 11-14 are good with a design:
https://www.backyardchickens.com/threads/versions-of-chick-chairs-please.1166308/