Capitals right wing Mike Knuble, left, bears down on Blue Jackets center R.J. Umberger. Washington’s win put the team past 100 points for the season. (Toni L. Sandys/WASHINGTON POST)

The Washington Capitals entered Thursday night’s contest against the Columbus Blue Jackets with six healthy defensemen. They exited it with an overtime win that pushed them over the 100-point plateau for the third consecutive season but with another injury on the blue line and discouraging details about a player already on the sideline.

Washington defeated Columbus, 4-3, at Verizon Center on an overtime goal by former Blue Jacket Jason Chimera, pulling within a point of the Philadelphia Flyers atop the Eastern Conference standings. But that would prove to be something of a footnote with injuries continuing to mount on defense.

Dennis Wideman missed the contest with what a team source confirmed as a hematoma in his right leg. The injury, first reported by TSN’s Bob McKenzie, occurred when Wideman was hit Tuesday by the Carolina Hurricanes’ Tuomo Ruutu. There is no timetable for the defenseman’s return.

A hematoma occurs when blood leaks from a broken blood vessel, artery or capillary into tissue where it doesn’t belong, such as a muscle. It can result in compartment syndrome, which involves increased pressure in a muscle compartment and can lead to permanent muscle or nerve damage. The same team source, who was not authorized to speak publicly about the injury, said Wideman has compartment syndrome but that damage to the leg appears limited.

According to veteran right wing Mike Knuble, the team is preparing for Wideman to miss at least two weeks, perhaps many more.

“He’s been firing off some pictures [of his injured leg], too, and they’re pretty graphic ,” Knuble said, describing Wideman’s swollen leg and where it was cut to drain the blood and relieve the pressure. “It’s pretty grotesque how Dennis is opened up right now. I think he’s pretty much high all the time to deal with the pain.”

The initial report of Wideman’s injury came shortly after defenseman John Erskine left early in the second period of the game against the Blue Jackets.

Coach Bruce Boudreau said Erskine is day-to-day, that it was precautionary to hold him out of the rest of the game and that the defenseman did not injure his hand in a fight with Columbus’s Jared Boll in the first period. Erskine skated one shift after serving the fighting major and missed the final 36 minutes of the game.

If Erskine should miss any time the Capitals likely will be forced to recall someone from the American Hockey League’s Hershey Bears, though they have used forwards on defense on occasion. It’s the latest kick to the Capitals, who are already without Mike Green (concussion), Tom Poti (groin) and Wideman.

“Just seemed like last week we were getting guys back, got Jason [Arnott], got Alex [Ovechkin], a couple other guys that are nursing stuff here and there, and now they seem to be dropping,” Knuble said. “John, I’m sure he’ll be back, but all of a sudden you were pretty deep, pretty comfortable and now you’re searching for guys that can play.”

That challenge was demonstrated once Erskine left the contest against Columbus. Washington (45-22-11, 101 points) held a 1-0 lead off a goal by John Carlson, who was playing in his 100th NHL game, 1 minute 39 seconds into the first period. Fast-forward to the middle of the second period, with the Capitals playing with a rotation of five defensemen.

Both Carlson and Karl Alzner were at the end of a grueling, 1:39 shift when they, along with Capitals forwards, didn’t pick up Antoine Vermette, who tied the contest at 1 from in in front of the net with 11:10 elapsed in the second. It was the first of four goals in 2:17. Knuble gave Washington a 2-1 lead 82 seconds later, then the Blue Jackets’ Fedor Tyutin and Arnott scored 13 seconds apart to make it 3-2 Washington.

Boudreau absolved Michal Neuvirth (20 saves), who was starting for the first time against Columbus and the first time since March 22, of blame for the tallies.

“The goals that went in were hard to stop,” Boudreau said. “More importantly, when the game’s on the line, he’s there. He had to make some really good saves at the end to preserve” the win.

The Blue Jackets (34-31-12, 81 points) carried the play for the better part of the third period. With less than six minutes left, Scottie Upshall fired over Neuvirth’s left shoulder to tie the game and eventually force overtime. Although the Capitals would prevail on Chimera’s first goal since Feb. 4, the players understand that with the absences from their defense they need to be particularly aware of their play in their own zone.

“We didn’t do a very good job of it tonight,” Arnott said. “There was a lot of bouncing pucks and a lot of nonchalant plays that we don’t normally make and we did it tonight. Obviously, we’re going to correct that. We’ve got to come back a little bit more and be conscious of it. We are missing two key guys back there.”