When it's big blocks like that then it's almost certainly the players tickets which haven't been taken up. They should go back on sale really even if day before. Seen it a few times before and it's always been games quite far away in **** weather funnily enough.
There were cheaper ones but I wanted a decent view given how ****e I've heard the view is in some parts there. Probably have some geared up knobhead trying to nick my seat now.