If Sobotka doesn't come back that should pressure Army into trading Shattenkirk. Unless he sees the Blues as a non-playoff team and thinks he can get more at the TDL
I think in first place Army should have trade Sobotka's rights if he has really hold on and waited will he come or not back and reason he couldn't acquire needed fill for team in this off-season.
I love Sobotka, but if case is this difficult with him (he come or not) you can't let that affect your off-season moves and you need to think for team and long term and not be stubborn and hold Sobotka's 'value', you trade him lets say late round pick, but case you trade him so you can aqcuire your need and move on ffs. You set timeframe for him and if nothing won't happend before it you trade him.
Btw IF the reason has been Army waiting for first Sobotka come and then just trade Shattery Army should be fired immediately.