You can use fmrte and load the game and go onto his fmrte profile and untick the injury box . Note well that he won't be above 70 % fit probably . So you'll Also have to change his jadeness and his match fitness if you want him absolutely fit .
Use the search in future mate. This has been asked many times before. If you need anymore help feel free to PM you and I'll do all the work for you and give you an answer.