O’Brien had an absolute rollercoaster of a year, heading to the USHL in a change of scenery that did not work out well for him, before coming back to Portland to cap his season alongside familiar faces. He’s a responsible 200-foot player who is attentive to positioning and stays above pucks so that he can support play or put himself in a position to jump into a lane to make an offensive play or defensive stop. His skating speed and stride aren’t elite, but he can move efficiently and subtly give off false information, getting opponents to move in directions he wants them to. At times, though, it appears he can collapse through his hips. There’s little flash, but a lot of effectiveness, in how he handles pucks, and there’s more depth in the details to his game than pure skill expression. He’s crafty and methodical with how he moves pucks, and can show patience and dexterity with his approach, allowing for a play to evolve and then finding the best option instead of throwing pucks blindly. He’s smaller but strong through his core, and can hold pucks by angling his body away from pressure and keeping his hands hidden. Really doesn’t dust pucks a whole lot or play a game that’s overly dynamic, but rather centers his game around efficiency. Tempers his offense as a play driver, but that allows him to be a high option who occasionally rotates low or plays off angles and behind defender’s backs to know when to attack. Defensively he can dictate routes of attackers by taking good angles and providing a steady presence with proactive stick detail. He is a bit weak in battles, but he has timing. His problem isn’t how he sees the ice, but rather how he adapts to adversity and solves problems, as he’s not the most creative player. Some teams will be a bit gun-shy after his rocky start, but there’s still something to work with here.

– FCHockey’s 2021 NHL Draft Guide