But Saturday's game against the Flyers was a strong reminder of the force the former second-round pick can be on the back end. Carlo played 25 minutes, 41 seconds - his highest ice time of the season - and, with McAvoy, Chara, and Kevan Miller all spending time in the box, was the rock behind the B's 6-for-6 afternoon on the penalty kill.
"That's something I pride myself on, the area of my game that I want to show that I'm growing and that they can trust me in," Carlo said after the team's optional practice at Bridgestone Arena on Sunday afternoon. "I had a lot of fun going out there…I love to block shots, I love to be in those lanes in those situations. It was good for me to be out in that situation. For myself, just gaining that experience is a great part as well."
Carlo is a plus-5 through 24 games this season and has continued to be a dependable presence for Cassidy and assistant coach Kevin Dean, ranking sixth on the team time in time on ice per game (19:09). It is his offensive game that Boston is hoping continues to develop.
The 6-foot-5, 208-pounder went six games without landing a shot on goal, before firing two on Brian Elliot against Philadelphia, and has has just four assists without a goal after a 6-goal, 10-assist campaign during his rookie season. Cassidy believes the dip in offense is more a result of the team's current approach with so many injuries up front, rather than any serious drop off in Carlo's play.
"I think when we have a full lineup we'll be able to make more plays off the rush," Cassidy explained. "That will allow all the D to get their numbers up a little bit. Some of that is the product of him being assertive and us pushing him a little bit more and some of it is we don't make as many clean entries so that the D can join…we're starting to see more of it.
"I would expect that that part of his game would go up in the second half because it's there, there's some of it there, I think. He's never going to be what you call a high-end offensive defenseman - he's not on our power play - that's not going to allow him the points, but I think there's some secondary offense that we can get out of him. All in all, we're pleased with his year."
Carlo has also had to adjust to playing with a new partner. While he saw some shutdown time with Chara on Saturday against Philadelphia, the 21-year-old has been paired with Torey Krug for much of the last six weeks with Adam McQuaid sidelined by a broken fibula.
"I feel like it's going well. I feel like we're starting to develop chemistry," said Carlo. "It's fun to play with him and have a guy who is offensive like that and makes good plays getting out of the zone. When he can jump up and I can stay back a little bit, I'll definitely do that for him.
"But he encourages me as well to go up…I hear him on the ice [telling me] to get up the ice. It's a good situation and I feel like as we breakout the puck and develop that chemistry a little more we'll have those opportunities up the ice."