That could be from the vet's lettuce diet.
Vet visits are often disappointing with chickens. We have hundreds of vets in our area and there are only 3 or 4 good avian vets with poultry experience. That ratio is not uncommon around the world. Most of the vets who train intensively with poultry go into the commercial industry. Dog and cat vets are mostly worthless in this area.
Sounds like he is trying to recover on his own.
Giving him a friend will boost his spirits.
Alabama is warmer than here and possibly wetter so worms can be more problematic there. If he isn't real weak, it may not hurt to worm again. What were you planning on using to worm him? Another option is an herbal wormer that you can use regardless of his physical condition. This 2 formula product gets good results.
http://www.fiascofarm.com/herbs/mollysherbals.php/categories/herbal-wormer
If you moisten the feed, stick with the flock raiser. The scrambled eggs are great.
Make sure he's getting access to adult size grit.
Many will disagree with the following advice but since you don't really know what is wrong with him it warrants being careful with feeding. And you may not know how he was fed in his previous life.
If he continues to improve over the next couple days, I'd cut back on the protein. You can do that by giving him some scratch, oats, wheat, barley or corn. Oats in warm weather is my preference. If your AF feed is 18% protein, a ratio of 6 parts feed to 4 parts grain will yield about 15% protein. If it is 20% protein, a ratio of 7 parts feed to 5 parts grain gets about 15% crude protein.
The reason for this is that a healthy rooster does just fine on about 13% protein. Excess protein is hard on the liver.
The problem with the grain/all flock mix is that some of the essential amino acids will be low. So if you continue this route, continue to offer some animal protein a couple times a week: eggs, meat, fish, etc..
I would continue to add Nutri-Drench to his water at the dosage on the bottle.
Lay off the layer feed, excess calcium is hard on the kidneys.
So to summarize, worm if you choose.
Lower calcium and crude protein while still providing animal protein and nutri-drench.