The Capitals had to find their own internal motivation for the final two games of the NHL's regular season. With their spot in the Stanley Cup playoffs sealed, the results of games with the Ottawa Senators and Boston Bruins are essentially meaningless.

But don't tell that to coach Adam Oates. He was willing to make a switch in goal from Braden Holtby to Michal Neuvirth on Thursday night against the Senators. But that was as far as he'd go. The forward lines and defensive pairings remained intact in a 2-1 overtime loss at Verizon Center.

"Quite honestly, I think we're going to play the same exact way," Oates said earlier this week. "Guys are used to their minutes, and because of that, you're used to your conditioning based on that. We've got to win games, we need points. Obviously if you win a round, you want to re-seed yourself and put yourself in a good position. I don't want the guys to affect their conditioning. That's a very important thing."

Other teams around the NHL, including Ottawa, were still fighting desperately for a playoff spot or -- at the very least -- a better position. No so for Washington, which was locked into the No. 3 seed in the Eastern Conference even before Thursday's games.

That left the Caps' coaching staff walking a fine line: How much rest do you give players nursing bumps and bruises, and how much do you push for four standings points that don't do much to advance the cause?

"The schedule's different this year," Oates said earlier Thursday. "Ottawa could be a team you play in the playoffs, Boston could be a team we play in the playoffs. We can't have any let-downs."

It was a good plan, in theory. But the Caps were fighting human nature, too. They didn't have anything to play for and the Senators did. The game was relatively even until Ottawa forward Jakob Silfverberg deflected home a shot by defenseman Erik Karlsson at 12:35 of the second period. It was a meaningful moment for Karlsson, who was playing for the first time since sustaining a partially severed Achilles tendon in a Feb. 13 game against Pittsburgh. It was thought at the time that his season was over, but last year's Norris Trophy winner as the NHL's top defenseman has returned at the perfect time for the Senators.

Alex Ovechkin later tied the game at 1-1 when he skated onto a pretty aerial pass from teammate Marcus Johansson and went right around defenseman Chris Phillips before backhanding the puck past goalie Craig Anderson. That goal came at 8:31 of the third period. It was his NHL-best 32nd of the season. Sergei Gonchar scored the game-winning goal for Ottawa 47 seconds into overtime to secure the extra point for his team.

Ottawa (24-16-6, 54 points) beat the Caps (26-18-3, 55 points) for the third time this season to sweep the series and clinched a playoff spot with the victory. Washington is 10-2 over its last 12 games with both losses to the Senators, who are currently the No. 6 seed and would play the Caps in the first round.