Since being called up from the Binghamton Senators in early February, Jim O'Brien has grown into a key role player with the big club in Ottawa, which has led him to the playoffs (Andre Ringuette/NHLI via Getty Images).

It's not a dream anymore, Jim O'Brien.

The Ottawa Senators forward can't help smiling as he recalls the days of his youth back home in Minnesota, when the arrival of spring meant following his hockey heroes intently as they chased the Stanley Cup. All of it a magical scene to a young boy's eyes.

"You sit there, you watch it and you're just kind of excited," said O'Brien, the Senators' first-round pick in the 2007 NHL Entry Draft (29th overall). "You have your teams that you like, your players that you like and you're watching them and cheering for them. It almost feels like you go through the ups and downs with them."

All these years later, O'Brien is still riding that wave of playoff emotion. Except he's right in the middle of it as someone who's grown into a role of some importance with the Senators since his callup from the American Hockey League's Binghamton Senators at the beginning of February. He's been an effective penalty killer for head coach Paul MacLean and, even though he had the least ice time during Monday's 1-0 loss to the New York Rangers at Scotiabank Place, produced some of Ottawa's best scoring chances.

The wild, raucous scene at Scotiabank Place for Game 3 of the Eastern Conference quarter-final, the intensity of it all ... yes, O'Brien is truly living the dream these days.

"Coming in, I said (to myself) 'I've always been watching the Stanley Cup playoffs since I was a little boy and now this year, it's a little different,'" said O'Brien, a 23-year-old native of Maplewood, Minn. "I'm still going to be watching the other games, but now I'm playing in them, too. It's a pretty cool feeling."

O'Brien was first summoned from Binghamton on Feb. 3 to help fill the void at centre caused by the absence of Jesse Winchester, whose absence from the lineup due to a concussion wound up lasting almost until the end of March. While Winchester is back and saw duty on the Senators' top line on Monday night, there is no removing O'Brien from the lineup. He's been that effective.

Still, the 6-2, 200-pound centre never envisioned his callup lasting 28 games — including his first career National Hockey League goal back on Feb. 15 in Sunrise, Fla., against the Panthers (he's added two more since then, along with three assists) — and then carrying on into the playoffs.

"To be honest, when I got called up, I wasn't thinking much more ahead than just the day at hand," said O'Brien. "I've just got to get through this practice, I've got to make sure I'm getting better, I've got to make sure I'm good in this game, I'm doing this good ... so I mean no, I didn't really look ahead to the next week, let alone to the playoffs."

Now that he's here, O'Brien — one of the "Bingo Boys" on the current Senators roster who helped the B-Sens claim the Calder Cup a year ago — hopes to draw on that AHL playoff experience to help him now.

"Everything's up a level, but it's the same kind of stuff down there. Just not as big," O'Brien said of the AHL playoff grind. "You get the big emotional swings in the series and you get the ups and downs and changes in momentum. The only way to learn how to deal with it is to go through it a time or two. I'm feeling like I've gone through it (already). I feels like I'm better versed to handle it now."

Game 4 in the Sens-Rangers series goes Wednesday at Scotiabank Place (7:30 p.m., CBC, Team 1200), with the series shifting back to Madison Square Garden in New York for Game 5 on Saturday (7 p.m., CBC, Team 1200).