All well and good, but the defending Stanley Cup titlists spent 40 l-o-n-g and l-i-s-t-l-e-s-s minutes messing around, losing pucks, and otherwise doing a whole lot of nothing before finally getting to that one legitimate period of hockey. When the night was over, the only surprise was that they lost to the Senators by only a goal, 1-0, thanks mostly to the superb goaltending of their resident poet Vezinate, Tim Thomas.

OK, fine, it was their first game back from a long road trip that they wrapped up Saturday night with a 5-3 win over the Senators. We get it, the road takes its toll. But it was also their first game on Causeway Street since a 3-0 loss to the Rangers Feb. 14. For a bunch of guys with aspirations of manufacturing a Cup couplet, they have been spectacularly less than ordinary at home of late, going 1-4-0 in their last five at the Garden and without a win in regulation since nipping the Senators, 4-3, Jan. 31.

“The first two periods were painful to watch and to see,’’ acknowledged coach Claude Julien, noting he wished he had a way to “modify’’ the anticipated low tide of emotion his club brought to the game. “Our guys just didn’t have any legs. Our game was very, very slow.’’

If not for Thomas (do a Google search for those four words in the 2010-11 season), it would have been over well before the 40-minute mark. Thomas, though, was the one Bruin with his eyes wide open from the drop of the puck, leaving him with 30 saves after two periods and leaving his club a chance to escape with a point or two when it deserved, and ultimately got, far less.

The underlying issue here, before anyone buys fully into the “back home blues’’ bromide, is that the injury bugaboo has finally caught up with the Black-and-Gold. They have been without first-line right winger Nathan Horton (concussion) for 15 games. Speedy, versatile winger Rich Peverley has missed the last six games with a wrenched knee. Top four blue liner Johnny Boychuk, the latest to be concussed, missed last night’s loss and won’t be seen until next week at the earliest.

For those who’ve watched this team through the decades, the injury thing is a familiar lament, one that many grew tired of over the course of the 39 years it took the club to land another Cup. In part because of their workingman, lunch-pail style over the decades, too many of their seasons were derailed by damaged shoulders, knees, elbows, and noggins. While the great Oiler teams of the ’80s boasted of 400-plus goal seasons (five of them, in fact), the Bruins often were left to suffer the pain and disappointment of seasons that included 200- or 300-man games lost.

Over the last six weeks, coinciding with about when Horton left the lineup, the Bruins have been painfully slow to get out of the gate. Last night was the 17th time in their last 21 games that they have failed to enter the third period with a lead. They played 13 games in February, and like last night, trailed after two periods in eight of those games. They also lost all eight of those games. No surprise, really, given that they were outscored by a 15-1 margin in the first two periods of those games.

All of that accentuates the need for Messrs. Horton, Peverley, and Boychuk to get back as soon as possible. When healthy, as we saw in November and December, it’s a solid, heavy team that can grind its way to win after win after win, just as the conference-leading Rangers have been doing now for months. Minus three core players, however, it’s a club that lacks the ability to get out front from the start of games, pull away and bank points. The Bruins haven’t won back-to-back games since Jan. 10-12. To the contrary, they’ve twice logged back-to-back losses, including defeats in Winnipeg and St. Paul on that just-concluded road trip.

Horton wasn’t having a great year, but it’s clear now how much space he opened up for David Krejci (2-0-2 in his last 13 games) to wheel and deal. Peverley isn’t a dynamic scorer, but his speed and pluck are valuable and offer Julien many options. He was 1-3-4 in his five games leading up to his exit. Boychuk, signed to a three-year, $10 million extension last month, is a big part of the back line’s success. Losing Johnny Rocket was part of the reason management on Monday picked up shot-blocking Greg Zanon at the trade deadline.

What we know for sure, because of the Cup they won and their eye-popping November-December play, is that they are capable of delivering far more than the 11-11-1 we’ve seen over the last 23 games. But it’s also quite clear, that if not for Thomas, it’s a club that will be challenged to get out of the first round of the playoffs if the injured don’t return, or if one guy comes back just as another guy leaves. We’ve seen that all here before, and we’re seeing it again now.

Last night wasn’t just a home-again-back-from-the-road clunker. It was a night that fit in well with what has become a trend of slow starts, early deficits, and trying to steal a win instead of manufacturing it. As the record shows, that’s just not winning hockey.

Kevin Paul Dupont can be reached at dupont@globe.com.