That's okay!
The yolk is fairly small so I would expect that to be absorbed in half a day to a day or so. He probably wont have much interest in food in that time.
The biggest threat is probably infection, I'm not an expert, so someone else may have better comments on how it is looking currently, I'm not too sure about the cord around the leg situation, either.
Keep everything soft for him, puppy training pads may work well if he's already in the brooder. Don't put him with the others until he's done absorbing, make sure everything is clean and dry. Keep us updated!