Help!!! Slipped tendon?

[Sophbrownie]

I need some advice, I’m not sure if this is a slipped tendon or what. He’s only about 3 days old. He won’t put ANY pressure on it. I tried stretching and massaging, but nothing seems to change but it does cause pain. I tried splitting and hobbled but he still won’t use it. I want to be sure I’m pursuing the right treatment. Photos in the comments.

Should i just splint it for a day to see if that helps? I don't want to cause unnecessary stress or pain

 

[Sophbrownie]

 

[Sophbrownie]

As you can see, the tendon seems to be in line? It is swollen at the nub from him using it to get around. Now he is full flamingo since he is stronger in his one leg.