Thinking if I can nurse him till the first team then a big club might come in with a semi decent offer. talent is there. Inj is a **** shame
Keeping good physios around will help a lot ( Physiotherapy, Determination, Motivation, Fitness - to a much lesser extent, Working With Youngsters). Also look for a Man Management in a Head Physio.
When you give him game time, ensure to plan on games that have good weather and pitch conditions; a team that isn't physically aggressive; a duty that keeps him away from the heavy tackles, so stuff like DM(d), DLP(d/s), HB(d), A(d) would work as they tend to cover more and aren't aggressive going forward (also don't put him in the box for attacking set pieces); games with a strict referee (I typically call strict a referee with an avg rating above 6.00 and giving out more than 3 cards per game, counting a straight red as 3 yellows.); a minimum of 15 minutes so he can get a rating to influence his Consistency attribute (ideally aim for 20, just in case the sub doesn't happen in time.);
For training you can consider rotating his training load. Something like 2 weeks of having an individual training and one week off. His high professionalism would mean he would be less likely to get injured in training from doing silly things (and if the rest of the team has good professionalism (~13 or higher), they're less likely to injure him by doing something silly). If you're going to try and teach him a PPM, use him in matches less than you normally would to avoid a long injury layoff cancelling the training.
If you're looking to sell him, find a suitable tutor to up his Ambition as it aids in his development and gives him a better overall personality as both will help you get better prices.
I don't think he's a lost cause for now, yes he has a high Injury Prone stat, but it doesn't necessarily mean that he will get injured often. Just very likely to get injured.