can he move the wing normally? it could be broken. You need to take a careful look. He may need to have his wings bound with vetwrap to keep them still, or if just bruised then just time and tlc is needed.
paleness can be a sign of shock. Is he paler than normal?
have you examined him inch by inch and has he got any visible injuries? A spur could have punctured him somewhere hidden like under his wing for example. Do a thorough search. If not a wound, he could have bruising or a broken bone or an internal injury.
I would start with checking him over...