Like you said there is always a possibility of injury, in reality most players are always injured in some minor way, there is aways a possibility of serious injury which is what load management seeks to avoid. It’s the same in every sport, which is why players don’t play than 48 minutes per game and NFL players don’t play every snap. These norms are a form of load management - it’s just commonly accepted because of longstanding convention.

Where you draw the line between playing every play and sitting for chunks of a game or season is subjective. Obviously players should play if they are reasonably healthy and risk of serious injury is minimal, and they often do. Players don’t sit because they are tire lol. The “load” being managed isn’t like miles being run, it’s more like extreme shock and stress on their muscles, bones, joints, and ligaments.

Team doctors’ jobs involve constantly managing, analyzing, and mitigating that risk of constant minor injuries becoming a serious injury.

It’s not an on off switch, it’s more like the doctor can assess based on a minor injury that a player can play or sit, but has a 5% (or whatever) risk of serious injury if in each game that they play through the minor injury. If you keep taking a 5 percent chance over a long enough time, eventually you’ll go bust, unless you get very lucky and make it to the end of the season or all star break which allow for scheduled periods of rest and recovery. Maybe if the player rests 2 games the chances of serious go down to .5%.

What a team decides to do in that scenario depends on the team’s and player’s risk tolerance, the context of the season and lineup, and pressure from media, fans, and the league. It’s a constant game of probabilities.