By Matt Dolloff, CBS Boston

BOSTON (CBS) — After two straight years of missing the Stanley Cup Playoffs, the Boston Bruins have plenty of unfinished business and unanswered questions on the defense. But they may also have one at the center position that’s going largely unnoticed: what is David Krejci’s long-term outlook?

As the 30-year-old recovers from offseason hip surgery, the second major hip procedure of his career and the first on his left side, questions loom about his long-term durability and value. Krejci remains signed through the 2020-21 season with a $7.25 million cap hit, but he may not be playing nearly up to that number by that season when he approaches his mid-30s. While hip injuries are fairly common in hockey and aren’t necessarily a death knell for NHL careers, Krejci could face a particularly sharp decline with both hips now repaired, but vulnerable.

Skating motions tend to put a disproportionate amount of stress on hockey players’ hips compared to athletes in other sports. Hip problems can also lead to injuries in other vulnerable parts of the body like the knees or shoulders, and while many hip injuries can be played through, they can also cause a faster deterioration over time. The hips could be especially susceptible to further injuries if the problem is an impingement, an overgrowth of the hip bone that was the source of Krejci’s injuries to both hips.

Kevin Neeld, President of Endeavor Sports Performance in New Jersey and Strength & Conditioning Coach for the USA Hockey Women’s National Team, says players in Krejci’s situation inevitably experience a gradual physical breakdown after recovering from injuries like hip impingements – and it’s a problem that’s hard to block out of their minds.

“I think of [chronic hip injuries] like erosion. … These things develop and develop over time,” said Neeld. “And [players] can’t just forget about it.”

David Krejci of the Boston Bruins heads for the net against the Carolina Hurricanes during Game One of the Eastern Conference Semifinal Round of the 2009 Stanley Cup Playoffs on May 1, 2009. (Photo by Elsa/Getty Images)

David Krejci of the Boston Bruins heads for the net against the Carolina Hurricanes during Game One of the Eastern Conference Semifinal Round of the 2009 Stanley Cup Playoffs on May 1, 2009. (Photo by Elsa/Getty Images)

Krejci underwent successful surgery to repair an impingement in his right hip in June of 2009. He returned in time for the start of the 2009-10 season but took a step back in terms of offensive production, following up a 73-point season with just 52 in 79 games.

There were no major problems with Krejci’s hips until he suffered an injury to his left hip just before the start of the 2014-15 season. He played through it but experienced a similar drop-off in production, following up 0.86 points per game in 2013-14 with just 0.66 points per game in 2014-15. He opted to forego surgery at the time and ultimately sat out a month in 2015 with a partially torn MCL in his left knee – the same side as his injured hip. He notched just five assists in nine games upon returning.

Krejci certainly looked healthy as he started the 2015-16 season on a career-best pace with 33 points in 35 games, but missed 24 days with a shoulder injury. He scored 30 points in 37 games after returning but ultimately opted for hip surgery after, according to him, the time off the ice actually made his lingering hip injury worse. According to Dr. Rob Laprade, it’s common for hockey players to go a while without overt symptoms of hip injuries until the issue is “well advanced.”

Dr. Matt Tanneberg, a Certified Strength & Conditioning Specialist based in Phoenix, Ariz., believes that Krejci’s lingering hip issues and decision to avoid surgery directly contributed to his 2015 knee injury.

“The issues can all be related,” said Dr. Tanneberg in an email to CBS Boston. “When you have an injury [to the hips], your gait changes. You skate differently, you push off differently, which means you are putting stress on different areas more than you should.”

Dr. Tanneberg, who has worked with athletes from the NHL, NFL, MLB, NCAA, and the USA Track & Field team but does not have intimate knowledge of Krejci’s particular situation, theorized that he will be back to full strength within 4-5 months of the surgery, which should have him ready for the start of 2016-17. But how Krejci performs next season is anyone’s guess, and his now-deep and troubling history with hip problems and other injuries leaves him uniquely vulnerable to further complications.

“The medical staff of the Bruins will do the best that they can in order to get his strength level and range of motion back to as normal as possible, however, the hip will never be as good as it was before the surgery,” said Dr. Tanneberg.

Ominously, Dr. Tanneberg also alluded to the history of pro athletes who have retired early due to deteriorating hips. One of the most high-profile examples is all-too-close to home: Cam Neely.

Despite the popular opinion that chronic knee problems ended Neely’s career, a 1996 column in the Boston Globe said that it was actually chronic arthritis in the hips, caused by overcompensation from the knee injury, that ultimately forced Neely to hang up his skates at age 31. Then-Bruins president Harry Sinden said that doctors told him the same thing about Neely’s hip, but “I told the doctors that they don’t know what they are talking about.”

Cam Neely (Photo by Glenn Cratty/Getty Images)

Cam Neely (Photo by Glenn Cratty/Getty Images)

Former All-Star defenseman Ed Jovanovski also battled hip problems throughout the latter part of his career and made a surprise return to the ice in 2014 following a hip procedure from orthopedic surgeon Dr. Edwin Su, who described himself as “the career-ender.” The Florida Panthers ultimately waived Jovanovski, who retired in December of 2015 at age 39. Though “JovoCop” enjoyed a long career, the deterioration of his hips ostensibly robbed him of the chance to play into his 40s.

Could Krejci eventually suffer the same fate due to his history of hip injuries, and further problems caused by them in other areas of his body? The good news is, surgery has advanced enough where it is not as invasive as it was 20 years ago. But there’s no guarantee that another hip problem won’t resurface, or that it wouldn’t lead to more problems with Krejci’s lower body.

Further injuries could also affect Krejci’s value if the Bruins tried to trade him – and cause his current price tag to grossly overinflate if his production drops off at the tail end of his contract. Krejci’s current situation would certainly give prospective GMs pause.

Outside of a few productive stretches, Krejci’s overall track record when returning from, or playing through, problems with his hips, is not strong. With both hips now damaged, repaired, and vulnerable, it’s fair to question what the future holds. But it’s looking more and more like Krejci – and the Bruins – will simply have to play it out.

Matt Dolloff is a writer for CBSBostonSports.com. His opinions 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 mdolloff@985thesportshub.com.