I just checked to see if my memory was faulty and this was a "supporters" only option, but it appears not to be as I can see what I think you want and I am not a supporter currently.
Team - Roster - Click on the player name - player history (should be the default option in the orange box to the right of the player name in the upper-right of the screen - then scroll down to injury tracker at the bottom.
Examples using one of my own players that just returned from an injury : -
https://www.buzzerbeater.com/player/52930620/history.aspxand one of your own : -
https://www.buzzerbeater.com/player/54298161/history.aspx.