WILMINGTON, Mass. — Tyler Seguin appears destined to get his first taste of NHL playoff action after all, but the opportunity has come in a way no one involved with the Bruins had desired.

Center Patrice Bergeron suffered what has been diagnosed as a mild concussion in Friday's 5-1 series-clinching win over the Flyers and is expected to miss at least the start of the Eastern Conference finals against Tampa Bay.

No final decision on his replacement in the lineup has been made, but Bruins general manager Peter Chiarelli made it clear that obvious choice was almost assuredly going to be the one made, with Seguin getting his shot after being a healthy scratch in each of the club's first 11 playoff games.

"It's a discussion that we've had with the coaching staff and will have it again over the weekend," Chiarelli said at a news conference at Ristuccia Arena on Saturday. "We feel that he deserves a chance. He's been working actually quite hard in practice. We'll see where he fits in in the lineup, but that's a pretty safe assumption also [that Seguin will play]."

The other options for the Bruins are fellow rookies Jordan Caron and Jamie Arniel, who have been practicing with big club throughout the playoffs, but Chiarelli nipped any controversy in the bud by pretty much anointing Seguin as the choice. 

"It's a fairly safe assumption that Tyler would be the guy," Chiarelli said. "He's really put his nose to the grindstone in practice. I think watching from above, [seeing] the intensity and tenacity of the game [has helped prepare him]. Plus he's going to give us an offensive boost as well."

That offensive boost is questionable. Seguin had 11-11-22 totals in 74 games as a rookie this season, but managed just 1-1-2 totals and was a minus-4 in his final 20 games and had no points in his last 11. Seguin's struggles helped make him a healthy scratch six times in the final 10 weeks of the season.

After being unable to produce in the opportunities he received as the pressure increased in the stretch run toward the playoffs, it's hard to imagine Seguin making much of an impact at this stage of his career when he faces the added intensity of postseason action for the first time, especially after a layoff of more than a month. Chiarelli did try to temper expectations for the No. 2 overall pick of last year's draft, but he also praised Seguin's work in practice during his time out of the lineup in the first two rounds of the playoffs.

"There's a tendency, consciously or subconsciously, to lay off your work ethic when you know you're not playing, and I've been watching him in practice and his on-ice and his off-ice has been outstanding," Chiarelli said. "He's kept sharp, but having said that, it's hard to parachute someone in, especially a young player like that. So we'll see how he does."

The Bruins will also have to see where he fits into the lineup. Seguin is unlikely to step right into Bergeron's spot on the second line between Brad Marchand and Mark Recchi. Chris Kelly moved up to that position in the third period on Friday and after a strong start to the postseason (4-3-7, plus-7 in 11 games), Kelly is likely to stay in that role to start the next series.

"Kelly is a good two-way player," Chiarelli said. "He makes strong plays. We've seen him on that other line, and his style of play is not unlike Bergy's, so at first glance it looks like it would be a good fit."

As good as Kelly has been, however, it is still a major dropoff to go from Bergeron to Kelly, especially with how well Bergeron has been playing this postseason. Bergeron is tied for second in the league and leads the Bruins with 2-10-12 totals through 11 games, and is also a plus-7 while averaging 19:02 of ice time. Only David Krejci (20:45) has played more this postseason among the club's forwards. Beyond the offensive production, Bergeron is also one of the league's top defensive forwards, and shutting down a Lightning offense led by the likes of Steven Stamkos, Martin St. Louis and Vincent Lecavalier without Bergeron's presence in a shutdown role will be exponentially more difficult.

Bergeron brings even more than that to the table, however. He has emerged as one of the team's primary leaders both on and off the ice. Filling that void could prove even more difficult, though Chiarelli is confident in the character the club's other veterans have displayed this year.

"Whenever you take someone like that out of the lineup, you're obviously missing a key character component, a key leadership component," Chiarelli said. "But what I've seen from this team toward the end of the regular season and especially after the first two games against Montreal, is that there's been a real kind of growing, bonding chemistry and there's guys that have been stepping up in the room. I think you'll fill those voids with those guys."

Bergeron's absence will cause a ripple effect throughout the lineup. Gregory Campbell moved up from the fourth line to replace Kelly on the third unit with Rich Peverley and Michael Ryder on Friday. Campbell could stay there with Seguin eased into action with a limited role on the fourth line and possibly some time on the second power-play unit, or coach Claude Julien could keep the fourth line of Campbell, Daniel Paille and Shawn Thornton intact and insert Seguin alongside Peverley and Ryder.

"We're still talking about where he would fit in the lineup, whether it's center or wing and also what line," Chiarelli said.

Wherever Seguin slots in, don't expect him to replace Bergeron. That's a void that can't be filled by any one player, and the Bruins can only hope that everyone on the roster picking up their game a notch will be enough to overcome his absence.