Martin actually got injured as well on the collision with Bjork, which is fairly impressive considering the weight difference. I like Bjork quite a bit, and while Cassidy mentions him, I am still wondering about the timetable on his rehab. IIRC, he wasn't going to be recovered until early August according to the reports.
If that's the case, then I would not be penciling him into any lineups. Offseason training programs are essential for success in the NHL these days and if Bjork was unable to train until August, he will be behind the 8 ball for most of the year. At the very least, he will need to start his season in PRO and work himself into playing shape.