Yeah, this guy just happens to be my best (or one of the best at least) so I noticed this fairly quickly. Anyways, this player: https://cust12.myfootballnow.com/player/2144 shows injuries to both his ankle (50) and leg (66), however, none of the recent transactions show these injuries.
Last time he hurt either of those spots was game 2 of 2 seasons ago (ankle) and pre-season game 2 of the same season (leg).

What gives?

The transactions log only shows serious injuries.

It shows non serious as well, but it does seem like some injuries do not get registered anywhere.

They should show up in the play-by-play regardless of how serious they are, they only show up in the transaction log if they are above a certain threshold.