Who’s in net? Six NHL teams opening the playoffs Sunday won’t say. The Arizona Coyotes, Nashville Predators, Colorado Avalanche, Columbus Blue Jackets and Minnesota Wild all have uncertain goaltender situations going into their first game. The Presidents’ Trophy-winning Boston Bruins might not have starter Tuukka Rask for their round-robin game against the Philadelphia Flyers after he missed practice. Coach Bruce Cassidy said Rask “wasn’t feeling well” and that Jaroslav Halak would get the call if need be. That’s more than most coaches will say about who’s between the pipes — a playoff tradition even though it’s the middle of summer.