I have a story,
at that time I was injured players in the league 18 days,
and players that I just sold, well after the player was sold, I do not think that my players are buying the team a league with me, and after I watched the player I was instantly able to play ..

I first thought that the team that buys players that I've got a lot of booster treatments,

after that I try again to sell my players are injured again, this time I happened to have a team again that a level with me and the server as well ..

I fit in the transfer window open by chance it turns out there was a player that I sell, and I try to buy them with my team, after making the offer and successfully. turns players had been cured,,
so the conclusion even if you sell an injured player to another person, then the player is not injured.
thanks
I hope my story helps ...