In the Bruins’ 1-0 victory over the New Jersey Devils last night at the Garden, there were a few things that were quite evident. Jaromir Jagr has a little game left in his 41-year-old legs. Secondly, Tuukka Rask is your No. 1 goalie. And thirdly, Patrice Bergeron will be sorely missed for however long he’s out with a concussion. The game’s lone goal went off Jagr’s skate past Martin Brodeur, and Rask made it stand up by making 40 saves. With the Canadiens also winning, that sets up another game for first place in the Northeast Division tomorrow night in Montreal, which has been the case in all three games the teams have played this year. And it’s a good thing they weren’t playing the Habs last night instead of the 29th-ranked Devils offense or it would have been a much different outcome. The entire game was a chore for the Bruins (outshot 40-26) without their steady centerman Bergeron, none more so than for Tyler Seguin, who was getting his most high profile game in the pivot. It didn’t take him long to get a better understanding of all the work that his injured linemate does in the physically demanding job. “First shift I was like ‘Oh, Bergy! I appreciate you a lot more right now,’ ” said Seguin, who went 3-for-12 in the faceoff circle. Seguin centered Jagr and Brad Marchand on a line that, on paper, has a lot of potential. But it was at times a very difficult learning process, one that coach Claude Julien fully expected to see. “It was what we thought,” said Julien. “Tyler is obviously realizing probably how tough it is for Bergy to play that position, because in the ‘D’ zone there’s a lot of territory to cover as a centerman. And when pucks were going from one side to the other, he wasn’t always there. That’s the work in progress and that’s what we expected and that’s what he’s going to get used to. “But overall, that line was fine. You’ve got to remember there’s a Hall of Famer playing on that line playing with two young players who were probably looking for him a little too much versus making plays and taking shots like they should have. Hopefully that’ll wear off and it will get better.”