What the Bruins know beyond a doubt, halfway through the 2009-10 season, is that something is missing from their offensive attack.

“There is a bit of a hole in our top nine [forwards], either through injury or through deletions from last year,’’ said general manager Peter Chiarelli, who signed Satan to a one-year contract over the weekend. “So [the signing] is low risk. He is a good person and we’ll see how it goes. Now we have to be patient to work him into the lineup because he hasn’t played all year.’’

Forty games into the season, the Bruins, showing 105 in the “Goals For’’ column, are among the handful of weakest offensive teams in the league, alongside the scuffling likes of the Rangers, Islanders, Hurricanes, Red Wings, and Blues.

Marco Sturm’s 14 goals lead the way this year for a club that finished second only to Detroit for the NHL’s best offense in 2008-09. Most nights, the Bruins struggle to score as many as two goals, and if not for their solid defense and stellar netminding, last year’s regular-season Eastern Conference champion today would be looking at the likelihood of a lottery pick (and maybe two, courtesy of Toronto?) in the June draft.

“Our goals against [95] are where they have been,’’ noted coach Claude Julien, who mixed Satan into an hourlong workout yesterday morning at Ristuccia Arena as his club prepared to take on the Rangers tonight in Manhattan. “Where we’ve [been] hurt a little bit has been our production, our team production. A lot of individuals are below their normal production. Somehow we need to find that part of our game, and if we find that, I think we’ll be a much different team. And if today is any indication of what we can expect in second half, it was very positive.’’

Julien liked not only what he saw of Satan, but what he saw in the rest of his gang, who came to work with added hop in their strides. Perhaps, offered Julien, they were better rested after a day off Saturday, or they were clear-headed after finally putting the fanfare of Friday’s Winter Classic victory at Fenway Park behind them. More likely, some of them, especially some of those underperforming forwards, awoke yesterday morning to the reality that Satan was in town with a roster spot all but guaranteed, not to mention that injured winger Milan Lucic should be ready to go in a matter of days.

All of a sudden, there is real competition, not just for ice time but for the privilege of being told to suit up on any given night. If lethargy or complacency have stolen goals from the Boston roster this season, the shadows cast from the sticks of Satan and Lucic during yesterday’s workout might have been enough to get those psychological poachers to pack their bags.

“If the team is healthy, you’ve got two or three extra bodies, and that’s competition,’’ said Julien, who is committed to keeping seven defensemen on his roster, math that puts pressure on the forwards. “If we are going to be a better team, maybe we need that right now. There is nothing wrong with that. There are going to be some tough decisions on my end of it, I know that, but I’d rather have that than the easy ones.’’

Satan, a left wing with a career 354 goals and 721 points, most likely will take over Steve Begin’s job on the No. 1 line, with Marc Savard (C) and Sturm. Begin, an energy forward who has been one of the club’s most consistent performers this season, then would move onto one of the other three lines. Ditto for fellow left wing Lucic. All of which means two forwards currently working on lines 2 through 4 will be moved out of the lineup or possibly out of town - via trade or demotion.

According to Chiarelli, the only players who can be sent to Providence without passing through waivers are Vladimir Sobotka (C), Adam McQuaid (D), and Tuukka Rask (G). Clearly, Sobotka is the most vulnerable for a trip back down Route 95. High on pluck but short on finish, he currently centers the No. 4 energy line, flanked by Shawn Thornton and Byron Bitz. The obvious move would have Begin go back to his old job, working between Thornton and Bitz, and Sobotka swapping his Spoked-B for a Spoked-P.

It gets a little dicier when Lucic comes back, either later this week or next, from his extended absence because of a high ankle sprain. The winger most at risk right now is Blake Wheeler, now less than two calendar years removed from the University of Minnesota. His game is still more NCAA than NHL, frustrating in itself, but all the more so because he has the size (he’s 6 feet 5 inches, 210 pounds) and speed to be a force around the net. But he has only seven goals and 19 points and Friday was his 15th straight game without a goal. He went 0-5 -5 and was a minus-9 in December, and he’s got press box written all over him.

Not that Wheeler is alone. Hired gun Michael Ryder, now at the midpoint of a three-year, $12 million free agent deal, has gone a Montreal-like 10-6 -16 in the first half. He is a lean 2-0 -2 over his last nine games. If not for Wheeler, and the fact that he is a right wing, Ryder really would be feeling the heat from Satan and Lucic.

Satan figures he’s roughly a week from his first game of 2009-10. That’s the target Julien and Chiarelli gave him, and he figures he’ll know in 3-4 days if that is realistic. Since winning the Cup with the Penguins in June, he has been living in his Long Island home, staying sharp in recent weeks by skating with some of the Islanders’ spares and injured players.

“Obviously, if you look back into the history over the years, I was always an offensive player and that didn’t change,’’ said Satan, musing about how he might fit in with the Hub of Hockey. “I am going to help the team in that department. I have to learn the system and do everything that is necessary to be part of a team and not take it out of the system. Be good on both ends [of the ice], and create something offensively and help the team.’’

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