It's one of those where I can't see a positive reason for him not being involved. Earlier in the season we could put it down to not being rushed back and eased back in after a serious injury.
Now, the options are (unless I've missed any):
a) he's not as good as we thought and/or not performing well in training, meaning all the others are being picked over him on merit
b) he has some sort of personal issue (a la Helenius) which means he is not being picked
c) he has had a falling out with management and he is out in the cold
None of which bode particularly well for his future with us.