After all the previous postseason disappointments, this spring was supposed to be the one that ended differently for the Washington Capitals. Wednesday night, though, there would be no furious comeback, no heroics from the star-studded lineup to match the Tampa Bay Lightning’s killer instinct. There would be no win in the second round.

In a matter of six days and four games, the top-seeded Capitals were snuffed out of the Eastern Conference semifinals as the Lightning completed a tidy, four-game sweep with a 5-3 win at St. Pete Times Forum.

It was the second consecutive postseason that saw the Capitals exit the Stanley Cup playoffs prematurely as the No. 1 seed in the East. But this latest defeat was perhaps even more unexpected because it came after they showed signs of having turned a corner by dispatching the New York Rangers in five games in the first round.

“You always think when you win in five games, you have a good chance, and after first loss we was not upset enough,” star winger Alex Ovechkin said. “After second [loss], after third we was ready to go, but again something been wrong and we don’t win the game.”

The Capitals have not advanced beyond the second round of the playoffs in the four postseason trips during Coach Bruce Boudreau’s tenure, during which they are 17-20. They haven’t done it since 1998, the year they were swept by Detroit in the Stanley Cup finals.

The rapid exit only leads to more questions about what is missing from the Capitals’ makeup to succeed in the playoffs. After a year of waiting for redemption following the shocking loss to the Montreal Canadiens in seven games in 2010 after leading three games to one, it’s still unclear whether the Capitals have become any more adept at handling staunch playoff pressure.

“It just [stinks] to finish this way,” rookie defenseman John Carlson said, “because we were good enough to do special things.”

Following the loss to the Canadiens last year, General Manager George McPhee elected to keep most of the same team intact. But with another long summer beginning Thursday, the players accept that there likely will be some alterations to the team.

“To blow it up or change it, I think that’s a real knee-jerk, and George isn’t like that,” veteran Mike Knuble said when asked if he expected changes. “Will there be changes? Of course there’s going to be, and who knows what it is going to be, probably rightfully so.”

When Tampa Bay continued to push in every game, Washington couldn’t counter the performance of both opposing star players and grinders. In Game 4 it was one of the latter. Role player Sean Bergenheim jumped to the fore and recorded two goals, including the game-winner, to knock the Capitals on their heels as goaltender Dwayne Roloson made 33 saves.

It wasn’t until a tally by Martin St. Louis extended Tampa Bay’s lead to three goals with 3 minutes and 8 seconds remaining in regulation, though, that Boudreau said he wasn’t sure if his team would be able to come back.

“When they made this 5-2, I thought, ‘OK, this is going to be tough,’ ” said Boudreau, whose job security has been questioned since the possibility of a sweep neared reality. “Even before then, I thought, ‘We’re going to find a way.’ They want it too much and they’ve come back all year in dire straits, and I still thought we were going to tie it up.”

While the Lightning received offensive contributions up and down its lineup, Ovechkin and Carlson were the only Capitals to score two goals in the series. Ovechkin was the only player to reach four points.

Tampa Bay had less than 48 hours between its win over the Pittsburgh Penguins in seven games and the semifinal series against Washington, which had five days off between rounds. The Lightning, though, pounced on its Southeast Division rival.

“I thought we played well, but I think throughout the whole series they were the hungrier team,” veteran Matt Bradley said. “They did little things to win the games, and they won all of them.”

While each of the contests ultimately wrapped up close on the scoreboard, in the locker room afterward the Capitals expressed frustration at the way they would play well, only to falter quickly thereafter. The largest deficiency was in the third periods, where the Capitals entered trailing in all but one game, only to have the Lightning outscore them 6-2.

“I don’t think we had one complete game, which is the sad thing,” defenseman Karl Alzner said. “We’ve managed to squeak out a lot of wins without having to play 60 minutes, which is good, I guess. You kind of brush it under the rug when we’re playing so well, to be able to come back in the third period and win. It’s the playoffs; you can’t do that.”