With the Washington Capitals’ second-round playoff series against the Pittsburgh Penguins opening on Thursday, the Capitals are inching toward being fully healthy.

Defenseman Karl Alzner, who has missed the past four games with an undisclosed upper-body injury, practiced on Tuesday and said it was the most on-ice work he’s done since being ruled out for Game 3 of Washington’s first-round series against Toronto. Alzner said he’s “not sure” he’ll be ready for Game 1 against Pittsburgh on Thursday, but added that he is “progressing.”

Washington won three of the games Alzner missed, with Nate Schmidt playing on a pairing with John Carlson in place of Alzner. Schmidt was a plus-four in those four games and recorded two assists. Asked if he expects to get back into the lineup when he’s healthy, Alzner said, “I think so. Yeah, I didn’t really think about that. I guess that’s a good point. But yeah, I’m not too sure. I hope so, I guess.”

Capitals Coach Barry Trotz was asked the same question. “Possibly. We’re not there yet, so I’m going to be vague to you,” he said.

Before this recent injury, Alzner had played in 599 consecutive games, including the playoffs, and he spent most of this season on a top pairing with Carlson. He leads the team in blocked shots and is one of its top defensemen on the penalty kill.

“It’s very, very frustrating, especially at this point of the year,” Alzner said. “You can handle it a little more in the regular season but to watch the guys go to battle and have the feeling of being a team, it’s unfortunate to miss that. But at the same time I know that in the long run, it’s the best thing for the team and clearly was the right choice.”

Capitals center Lars Eller missed practice Tuesday for what the team said was a maintenance day; Trotz said he thinks Eller will practice on Wednesday. Winger Tom Wilson left practice early after he “took a stinger off the foot,” Trotz said, but added that he’s “fine.” Captain Alex Ovechkin left practice because of an equipment issue and then didn’t return.

“His skate broke,” Trotz said. “I said, ‘You didn’t have another pair?’ He said, ‘I couldn’t find them.’ I don’t know what happened.”