Nicklas Backstrom missed 40 games with a concussion last season, but returned in time for the playoffs. (Jonathan Newton/The Washington Post)

When the truncated NHL season finally starts on Jan. 19, the Washington Capitals may be without their top center.

Nicklas Backstrom hasn’t played since he fell awkwardly into the boards while in Russia during the lockout, and after he went to see a specialist this week, there’s growing concern that he may have suffered another concussion.

Backstrom suffered the injury, which was initially described as a neck problem, on Dec. 26, when he was playing for Dynamo Moscow of the Kontinental Hockey League.

The 25-year-old Swede, who missed 40 games with a concussion last season, hasn’t skated since returning to town on Sunday. Alex Ovechkin, who also played for Dynamo Moscow during the lockout, used the word “dizzy” when asked to describe his teammate’s status.

On Wednesday, the Capitals confirmed that Backstrom traveled to Michigan to see a specialist. His visit to a specialist was first reported by the blog Russian Machine Never Breaks.

“Nick and his agent informed us that they are being proactive with his injury and decided to visit a specialist prior to training camp,” Capitals spokesman Sergey Kocharov said. “Obviously, as you know, until camp officially starts, teams cannot perform physicals on any player.”

The Capitals have not disclosed details about the nature of Backstrom’s injury. General Manager George McPhee said he couldn’t comment on the center’s health until the new collective bargaining agreement is ratified by players and Backstrom can be evaluated by the Capitals’ medical personnel, which may not happen until Sunday. Calls and e-mails to Backstrom’s agent were not returned Wednesday.

“He’s a little disappointed at the timing of it right now,” Troy Brouwer said of Backstrom’s mind-set. “He wants to be in camp, he wants to be around the guys, and I think that’s what kills him the most. He kind of feels like he’s letting his teammates down, but we know how finicky injuries can be and we know that he wants to be here and that’s enough. When he gets healthy, we want him back as soon as possible, but a healthy, fully healthy, Nicky Backstrom.”

If Backstrom is unable to pass his training camp physical, the team will not have to pay him his pro-rated $6 million salary until he is medically cleared, because he was injured during the lockout.

Making do without Backstrom is far from an easy task, as the Capitals learned last season. When Backstrom was sidelined by a concussion for nearly three months after being elbowed in the head by Rene Bourque on Jan. 3, 2012, Washington was devoid of its most skilled passer and top playmaker on the ice, as well as one of its biggest behind-the-scenes leaders.

“Nicky is one of our go-to guys in the locker room, our go-to guys on the ice,” Matt Hendricks said. “He’s a leader on our team and we’re going to miss him, without a doubt. We’re going to miss the way he plays and the way he produces, but we’re going to do our best to win hockey games without him if he’s not going to be around.”

Should Backstrom miss any amount of time in the upcoming 48-game season, there will be compounding pressure on the Capitals’ other centers — especially Mike Ribeiro — to step up. Acquired on a draft-day trade to fill Washington’s need for a No. 2 center, Ribeiro has recorded no fewer than 51 points in each of the past seven seasons and has veteran playmaking ability.

But there’s no real way to replace Backstrom’s daily impact on the Capitals offensively, defensively or in the room.

“I think this team revolves around Nicky Backstrom,” Brouwer said. “The way he controls the play, controls the puck. When he’s out there, thinking clearly, making sure he’s making smart plays, there’s not many players better than him.”

Capitals note: The NHL’s Board of Governors voted unanimously to ratify the new collective bargaining agreement Wednesday in New York. The process won’t be complete, however, until the NHLPA’s roughly 750 members vote to approve the deal as well. That process likely won’t be complete until Saturday.

NHL Commissioner Gary Bettman told reporters in New York that the league will not release the 2013 schedule until the players’ ratification process ends.