Milan is certainly considering the risks of Boniface's knee injury. Although it is reported that Milan has received assurances regarding Boniface's readiness and health. But if he only plays for a few weeks and does not contribute much to the team, Milan certainly will not waste money on Boniface. Rumor has it, Milan also has several other names as substitutes for Boniface.
Looking out the whole Victor Boniface saga and his injuries I don't know if Milan will still be interested to continue the deal after seeing the level of his knee injury, though I know that Victor Boniface has not been injured lately but if the deal is completed and he becomes a Milan regular starter he will not fail to deliver and contribute to the growth of the team because he is a player who has a very good way of scoring goals because he is full of strength. Milan is not going to waste money on him they will get what they spent money for the player has also assured them that the injury happened a long time ago but it hasn't made him to stop playing well for his German team Bayer Leverkusen.