What does 'out indefinitely' mean in the NFL?
Usually, NFL teams have tentative or precise knowledge of the return date of their players from injury. Team doctors and medical professionals can predict the probable timetable based on the severity of the injury and the subsequent recovery and rehabilitation.
However, in some cases, teams are unsure about how much time a player will miss through injury. In those instances, the team declares the player's status as "out indefinitely."
It usually means that a player has suffered a significant injury and it's difficult to predict how much time he'll miss.
NFL players with indefinite timetables to return
Indianapolis Colts quarterback Carson Wentz suffered a foot injury during training camp last Saturday.
The team was unsure how severe the injury was, so they declared him out for an indefinite period at the time.
Since then, Wentz elected to have surgery to remove a bone from his foot, and will now be sidelined for five to 12 weeks. With the surgery, his recovery period is not a mystery anymore.
You can see that it's an extensive timetable that ranges from the best scenario to the worst. At best, Wentz would only miss a couple of weeks to start the regular season. In the worst-case scenario, he could also be out until November.
The keyword for those injuries: healing
It's impossible to predict how the human body will react to a certain injury.
This can be both a blessing and a curse for NFL teams. If a player is out indefinitely, it means that he can be out for the whole season, but it also means that a can happen, and the player can be back on the field sooner rather than later.
If an important player is out for an extended time - say, Dee Ford with a back injury during the 2020 NFL season - but you can't predict if he'll be back next week, NFL teams won't put him on injury reserve, which means he'll be out for at least three weeks even if he's healthy.
However, if his injury doesn't heal and his team doesn't put him on IR hoping that he can return, then a roster spot is wasted. It's a massive problem for teams during the short regular season the NFL possesses.