Players are expected to sign up to a code of conduct, which is upheld by the coaching staff and the players leadership group. That code includes a whole raft of big and small things like timeliness, missing training, dodging recovery, leaving their gear behind, missing the team bus, ducking their specialised training, not meeting the weight and fitness targets that are established in pre season etc etc. Stuff that may seem trivial to outsiders but it's considered important enough to the team to have mandated punishment, which can range from extra laps after training to being dropped for repeat offences. Most teams keep it amongst themselves, it rarely gets out into the media for obvious reasons. Bellamy is notorious for his ultra strict regimen, it's take no prisoners with him and the players buy into it or they go elsewhere.
Personally I applaud that approach, which has a long Bulldogs history even back to Kevin Ryan's time where he dealt out not exactly PC discipline.
Go Dogs