I'm don't think it can but I was sure and was just curious to know. I've noticed that players can be given dramatic changes in injury proneness between different versions of FM so should it be able to change in game?
There's loads of ways a player's proneness could change IRL... for example if you break your shinbone, assuming it has healed properly supposedly you're less likely to break that bone again in the future (because bones heal thicker than they started off, I believe - I could be wrong about this, I'm not a doctor), whereas you might be completely injury free for all your early years but then have a horrific knee injury that keeps recurring forever after but you'd still not be necessarily "prone" to other injuries.
Injury proneness should also only apply to chronic type injuries: tendon and ligament injuries, concussions, etc. Injuries involving broken bones are a matter of chance and shouldnt fall under this category.