"He's 100 percent healthy, so let's get that out of the way," Boudreau said at the team's practice facility on Friday.
"I heard a couple people say last night that he might be playing hurt. We're making excuses for him. He just didn't have a great game."
Ovechkin, the two-time defending NHL MVP, became the focal point of the top-seeded Caps' struggles in a 3-2 overtime loss to the eighth-seeded Montreal Canadiens in Game 1. Before the series started, Ovechkin said he was healthy, unlike last season when he battled a wrist injury.
"Maybe I was too excited or something," Ovechkin said. "We didn't play our game at all, especially me. I didn't play my game. ... When you think about it a lot, you can get too excited, too nervous."
He said the level of nerves he dealt with doesn't have anything to do with his promotion to team captain earlier this season.
"I'm still the same guy," Ovechkin said. "I'm still the same player."
Montreal defenseman Jarolav Spacek and Marc-Andre Bergeron received most of the credit for neutralizing Ovechkin, although the Habs used a variety of blueliners in Game 1 against him.
"They did a good job of having a tight gap against him," said Capitals forward Brendan Morrison, a healthy scratch in Game 1. "They didn't let him wind up. He likes to get the puck wide and every time he tried, there was a defenseman right in his face. He really couldn't get his legs going."
But Boudreau said it wasn't like Ovechkin hadn't seen that type of defense before.
"It's no secret," Boudreau said. "Everybody plays against him like that. But the deal is that when he's at the top of his game, it doesn't matter how they're playing him."
Also troublesome for the Caps offense is that they have failed to score in their last 11 power play opportunities, including going 0-for-4 in Game 1.