Something seems a little off with this. It's reported that Demko is still not %100 - not that he has had a setback. That means that they would have been aware of the situation all along. This management group has been among the most aggressive in the league, so I find it odd that nothing has been done, if they are looking at starting the season for any considerable length of time with Silovs/Patera - who have a combined 25 NHL games played. I get the impression that they still think Demko will be ready for camp.
Most professional athletes have a nagging, persistent injury by the mid-point of their careers, whether it's back spasms, tendonitis, even arthritis is surprisingly common. In some cases these can become career ending, in others they can be easily worked through with physio, stretching, massage etc.
My guess is Demko has something like this and it's proving to be more serious than initially thought. The doctors, trainers, and even Demko may have all thought he'd be fine by now, told management as much, and they operated under that assumption.
Very murky situation overall, but the Canucks should be fine. In the second half of last year became a defensive juggernaut, Tocchet's coaching style and emphasis on protecting the middle of the ice is designed to be easy on goalies. I reckon Demko will be back, but I'd bet my life he gets less than 50 starts even if it's available for all 82.
Lankinen has gotta be the favorite. I bet he'll sign a cheap 1 year. Where else is he going to get a healthy number of starts on a good defensive team? Obviously no one is barging down his door this year, so why not raise your stock and try to cash in next year?