Greg Wyshynski: For any NHL team with a tenuous grip on a playoff spot, the phrase "week-to-week" is the last one you want to hear describing a goalie's injury. Yet here we are with starter Matt Murray, who was injured on Monday night against the Philadelphia Flyers and is "week-to-week." Funny how the hockey world works sometimes: The Penguins signed Antti Niemi in the offseason because they wanted to give Tristan Jarry, 22, more time to develop. Niemi was a disaster (0-3-3, .797 save percentage) and was put on waivers; Jarry ended up as Murray's understudy, and will now replace the lead for "weeks.