If Adam McQuaid hadn’t been up-ended by Matt Cooke in Saturday night’s loss to the Penguin in what Claude Julien termed a “cheap shot”, there’s a chance Dougie Hamilton might not have been played on Sunday. The 19-year-old rookie was a healthy scratch on Saturday and is in a battle with nine other able-bodied defensemen for six starting spots once the playoffs open up at the end of April. But on Sunday he played an efficient and mistake-free 19:45 of ice time in the 3-0 win over the Panthers at TD Garden, and scored the insurance goal for the Bruins in the second period after hopping over the boards and jumping into things mid-action. After Daniel Paille and Shawn Thornton battled to keep possession in the offensive zone, the puck bounced out to Hamilton at the right point and he launched a shot through traffic at the Florida net. The quick look to Zdeno Chara had the defenders in front of the rookie thinking he was going to pass to the other point, and that opened up just enough of a shooting lane for Hamilton. The shot whistled through a Gregory Campbell screen in front of the net, and ended as Hamilton’s fifth goal of his rookie season. “I think I saw [Zdeno Chara] there and I think it kind of opened up for me a little bit. I think the one guy went at it and opened up a lane for me,” said Hamilton, who led all B’s defensemen with five shots on net. “I think it tipped off something and from my angle I didn’t even see it go in. I heard it hit the post and then come out, so I wasn’t even sure it went in, but obviously pretty happy. “To get another one and make sure we had a little insurance was a very good thing.” It also ensured that the Bruins wouldn’t go through the same exercise in frustration as they did on Saturday when a 1-0 lead simply wasn’t good enough for the Black and Gold. A two goal cushion was exactly what Boston needed.