OTTAWA — Joe Morrow has been the forgotten man on the Bruins back line. Now it looks as though the 24-year-old afterthought will be pressed into a prime-time playoff role, the former first-round draft choice expected to suit up on defense Saturday in Game 2 of the Bruins-Senators series.

Morrow, who hasn’t played for the Boston varsity since Jan. 22, partnered in practice Friday with Kevan Miller, spelling the injured Colin Miller, who exited the lineup early in the second period of Boston’s 2-1 victory in Game 1.

“Do what you came here to do,’’ said Morrow, assessing his tentative situation. “I was born and bred to be a hockey player, so now it kind of comes naturally. I’ll keep it simple and play the game of hockey. It’s a simple game.’’

For the record, coach Bruce Cassidy, while noting that Morrow is the likely immediate remedy for the depleted blue line, did not fully commit to him suiting up for the 3 p.m matinee at Canadian Tire Center.

There is the chance, though slim, that Colin Miller could be OK. He did suit up for practice — unlike veteran center David Krejci — and it’s possible his wounded knee will recover overnight. It’s also a possibility, noted Cassidy, that the Bruins could reach down to AHL Providence for a hurry-up recall.

“We would consider Providence,’’ said Cassidy. “But at this juncture it will probably be Joe, simply because he’s been here. He’s played for us earlier. We are confident in him. We could change our mind, obviously, but that’s our plan.’’

Morrow, who became Bruins property in the July 4, 2013 deal that sent Tyler Seguin to Dallas, has played 65 NHL games, only 17 this season. Until now, he has been the eighth man in Boston’s seven-man rotation, a ranking that didn’t change even after Cassidy took over for the fired Claude Julien Feb. 7.

Asked if he sought clarification along the way as to why he has remained in the roster badlands, Morrow said, “You can, but it’s not going to solve any of your problems. I stopped asking questions a long time ago and just dealt with the circumstances. Being negative and thinking, ‘Why me? Why am I in this situation?’ is not going to help you. It’s not going to help anybody.

“You come to the rink every day. You know you are blessed to be with these guys and wake up and try to get better and be a better hockey player for when your chance comes.’’

As Friday’s practice shook out, captain Zdeno Chara paired with rookie Charlie McAvoy (fresh off his NHL debut). Another pairing brought together John-Michael Liles and Adam McQuaid. Which left Morrow and Kevan Miller, who looked at ease as they traded passes and worked the puck up ice.

“I will tell you this,’’ said Cassidy, his lineup also minus top-four blue liners Brandon Carlo and Torey Krug, “in Providence, when I had [Miller and Morrow] years ago, they were a good, solid shutdown pair for us.

“Now, that’s the American Hockey League, and I am dating myself a little, but that was probably three years ago, but there was a comfort level there. So that is probably how it would shape up if we went that way.’’

Morrow, originally a first-round pick of the Penguins (2011), has shown impressive flashes in his four Boston training camps. He is fast and can move the puck. For all his speed and finesse, though, he has been prone to costly booboos, leaving both Julien and now Cassidy to emphasize his need to build more reliability and dependability into his game.

“Any time you are not able to play in a hockey game, it’s frustrating,’’ said Morrow. “No one wants to practice all the time.

“You grow up wanting to play the game. You grow up wanting to be in the playoffs and play for the Stanley Cup. Yeah, it’s definitely frustrating, but at the same time, it’s the cards you’re dealt and you have to play them.’’

In his four years of junior hockey with Portland (WHL), noted Morrow, the Winterhawks three times made it to the playoff finals. In his mind, this is his time of year. Now he has to hope Cassidy has the same thing in mind.

“It’s the playoffs now, every game matters substantially more than the last one,’’ he said. “I’ve always loved the playoffs, right from when I played junior. I’ve always been a playoff player. I feel that’s where I kind of shine, so that’s what I plan to do.’’

Kevin Paul Dupont can be reached at kevin.dupont@globe.com. Follow him on Twitter @GlobeKPD.