By Matt Dolloff, CBS Boston

BOSTON (CBS) — The Bruins had enough injury concerns entering the playoffs on defense, but David Krejci’s sudden, mysterious upper-body injury pulled the rug out from under the offense as well.

READ MORE: 9 Injured At Back Bay MBTA Station After Escalator Malfunction

Krejci gave it a go in warmups before Wednesday’s series opener between the Bruins and Senators in the first round of the Stanley Cup Playoffs, but became a last-minute scratch before the team’s Game 1 win. Left with a sudden lack of depth down the middle, the Bruins made do with what they had and gutted out a great win without one of their most important forwards.

This is not to doubt Krejci’s injury or his toughness. There’s no chance that Krejci, who led the team in playoff scoring in both 2011 and 2013, is suddenly pulling himself out of playoff games because he’s just a little dinged up. This is a serious injury that could actually end up hurting the team if they sent Krejci out on the ice in his current state.

The question, here, is the nature of Krejci’s injury, what caused it, and what it means for the team moving forward.

Obviously, Krejci’s presence will be sorely missed in the current series against the Senators, and beyond if the Bruins can get past them. Krejci had a weak playoff in 2014, but so did the whole Bruins team in that bafflingly bad postseason performance. Before that, he consistently played like a Conn Smythe candidate in the playoffs. That’s a presence that can’t possibly be replaced.

READ MORE: First Afghan Refugees Arrive In Massachusetts

But the bigger concern for Krejci is not just short-term in this series against Ottawa, but for his long-term future in Boston. Although it’s unknown what Krejci’s upper-body injury entails and whatever caused it to happen, concerns about Krejci’s history of hip injuries could inevitably bubble back to the surface.

Krejci has an upper-body injury, so it’s not the hip right now. But injuries to the hips – especially in the case of Krejci, who has now had surgeries performed on both – can often lead to injuries in other parts of the body due to overcompensation.

It’s likely that Krejci’s upper-body injury isn’t related to the hip, but it’s hard not to renew the same long-term concerns that have lingered ever since his second hip surgery. And the long-term concerns for the Bruins with Krejci mostly stem from the fact that he’s under contract with the Bruins for the next four seasons at a cap hit of $7.25 million, with a no-movement clause over the next two years. He turns 31 years old on April 28.

In the current series, the Bruins could certainly use Krejci’s playmaking ability to make smart passes through the neutral zone that would consistently beat the Senators’ neutral zone trap defense. But in the near future, they could also use the sizable chunk of cap space that Krejci will take up as long as he’s in Boston, which could be needed for the team’s glut of talented young players who will hit restricted free agency in the coming years.

Krejci has played in 643 of a possible 704 regular season games since the start of 2008-09. He was one of only three Bruins to play in all 82 games this season (Brandon Carlo and Dominic Moore were the others). So his sudden playoff absence has to be a major concern, because he’s not missing playoff games without a serious injury. And it’s a painful reminder that Krejci’s injury concerns may not get any smaller from here.

MORE NEWS: Gas Leak In Lawrence Forces More Than 100 People Out Of Nearby Buildings

Matt Dolloff is a writer/producer for Any opinions expressed do not necessarily reflect that of CBS or 98.5 The Sports Hub. Have a news tip or comment for Matt? Follow him on Twitter @mattdolloff and email him at