It was almost too good to be true, and so the Bruins had to expect somebody would drop out of their lineup during a busy stretch of seven games in 11 days leading up to Christmas. That “somebody” turned out to be David Krejci, who was out for Monday night’s 7-2 win over the Columbus Blue Jackets with an upper-body injury that cropped up at the end of that day’s morning skate. Krejci has missed 13 games now this season, with the majority of them due to a bad back that has acted up at points this season. When healthy, Krejci has been pretty good with five goals and 14 points in 18 games, but the Bruins were able to survive without him by placing Ryan Spooner between Jake DeBrusk and Anders Bjork in a fast, skilled kid line. Each of those three forwards had points in the blowout win over the Blue Jackets, and the hope is that the Bruins will get more of that from them with another game together against the Buffalo Sabres on Tuesday night.