One week of injury spans out for 13 days (anywhere from one day to 13 days i believe) so then just add those up fr each additional week that he is injured. It can either be a very short and convenient injury or a little longer one. there is no way to tell exactly how long he is out for though.
The player will be healed fully and won't have an injured for 1 week by his name any longer once he is fully recovered which you can check by just looking at his page or your roster.
Murray/Harris/MPJ/Grant/Jokic - 2020 NBA Champs