Because hockey isn’t baseball, goals can’t be manufactured in methodical, time-tested steps. There is no getting a man to first, bunting him over to second, spraying the ball to right on a hit-and-run to bring in the tying run, sliding to the plate ahead of the tag.

But the Bruins, minus some of their top offensive performers for the foreseeable future, are reduced these days to trying to squeeze out whatever offense resides in a unit lacking David Krejci, David Backes, and power-play specialist Ryan Spooner. They are in the business of piecemeal goal scoring.

Exhibit A in the Black-and-Gold manufacturing shortage was Saturday night’s 3-2 loss to Washington at TD Garden, the Caps paced by a pair of goals by Tom Wilson and, of course, the requisite Alexander Ovechkin one-timer, left wing circle, a vintage piece from the Ovie Museum of Fine Darts.

The Bruins fell behind early, 2-0, cut the lead in half early in the second, but never were able to catch up, despite two goals (Nos. 7, 8) delivered by top-line right winger David Pastrnak.

“If you break the puck clean out of your own end,’’ said coach Bruce Cassidy, drawing on the baseball analogy, “and you are attacking, playing in their end, that’s the equivalent of manufacturing. Because they are just getting it out, changing, getting fresh legs, and eventually that wears on you. You are getting those building blocks.’’

The Bruins did that for one healthy stretch in the second, after the first of Pastrnak’s strikes cut the lead to 2-1. But it all fell apart when Wilson tipped home a long-range Brooks Orpik slapper for the 3-1 lead with 1:10 remaining in the second.

“Credit to them,’’ said Cassidy. “Tough pill to swallow, feeling like you’d outplayed them, got back in the game, and we still had the same deficit.’’

The frustration grew in the third period when the Bruins frittered away nearly all of eight power-play minutes, save for Pastrnak’s final strike with 2:32 remaining in regulation. The spirit killer came when Orpik was ushered off on a four-minute high-sticking call only 46 seconds into the third, a prime chance to cut into the deficit. Instead, the Caps twice had breakaway chances to score, and if not for alert stops by Tuukka Rask, the Bruins would have been knocked out of the building on the strength (or weakness) of their own man-advantage.

“We definitely have to get our offense by playing some sound defense,’’ noted top-line center Patrice Bergeron. “And going on the attack. When we get away from that, and try to cheat before the puck is out of our zone . . . we have to play smart defensive hockey that turns into offense.’’

The Bruins failed for a fifth time to turn a win into a winning streak. They are now 5-4-3 on the season, and have followed each victory with a loss (0-3-2).

The Caps had the 2 points all but deposited in the bank halfway through the first period, following the strikes by Wilson (7:01) and Ovechkin (13:06).

In their previous five home games, the Bruins trailed for only a collective 31 seconds. By the end the first period, they’d added 12:59 to their account, and the imbalance only grew to a total 52:59. They chased the lead and never caught it.

Wilson’s goal, his first of the season, came compliments of a puck that squibbed out of the left faceoff circle on a backhand attempt by Lars Eller that pingponged off Bergeron and Paul Postma.

Parked on the goal line, some 8 feet of the left post, the fast-thinking Wilson sniped it to the top shelf, beating Rask on the near (stick) side.

“I was surprised,’’ said Rask, “but I had to respect the guy [Eller] with the puck. So I got out of my post coverage. He tried to shoot it, I go butterfly [knees down], and all of a sudden it’s on his stick and in the back of the net. One of those, sometimes the bounces go your way, sometimes they don’t — in that case it didn’t.’’

Rask was backed by four goals on opening night, a 4-3 win over Nashville. In his seven starts since, the Bruins have scored but 12 goals — an average of 1.71 a night. Thin margin for error.

Ovechkin hammered in one of his classic one-time slappers from the left wing circle for his 11th goal this season. As pretty as it was, the set-up was even better, a laser feed from Evgeny Kuznetsov from the right halfwall. Kuznetsov saw the seam, exploited it, and Ovechkin promptly delivered career goal No. 569 on his ever-expanding Hall of Fame résumé.

The Bruins cut the deficit in half, 2-1, early in the second, with Pastrnak putting a nice finish off a leading pass from Bergeron, right wing, off the rush. Goal No. 7 for Pastrnak, who had been blanked in the previous four games.

The goal gave the Bruins a psychic boost and they looked sure to tie it, until Wilson connected for his second with a nifty tip off an Orpik long-range wrister.

Parked just inside the blue line, Orpik leaned into a rolling puck and fired his shot low toward the net. Wilson made the tip near his skates, and the puck jumped off of his stick and under the crossbar.