Maybe, just maybe, has anyone considered that he was made to train with reserves to gain fitness? Judging by how he was at times last season he didn't look the fitness you'd expect.
This situation is odd for sure but until we see what happens ultimately to Schweinsteiger I fail to see how it is that bad. Loads of players have played for reserve teams before when trying to pick up fitness, especially from injury.
Sure that could be a reason. I am just basing my comments on the idea that he has been demoted as what most reports have been speculating.