David Ortiz, here hitting a home run against the Phillies last week, is again expected to wield the monster bat for the Red Sox.

AP / Mike Carlson

DUNEDIN, Fla. — When the Red Sox tumbled last season into third place in the American League East — their lowest finish in the standings since 1997 — and saw their victory total dip to 86 — their lowest since 2001 — injuries and the ineffectiveness of the pitching staff were viewed as the culprits.

Injuries to Curt Schilling and Tim Wakefield decimated the rotation, forcing the Sox to seek replacements from the waiver wire (Kyle Snyder) and Double-A Portland (David Pauley). Newcomer Josh Beckett, a 17-game winner, was inconsistent and Mike Timlin looked every bit his 40 years of age over the second half of the season when he compiled a 6.06 ERA.

But the pitching issues obscured another shortcoming, one not usually associated with the Red Sox. After scoring 900 runs in each of the previous three seasons — a feat never before accomplished in franchise history — the 2006 Red Sox offense was only average.

The Sox scored 820 runs, ranking them sixth out of the 14 American League teams. By contrast, the New York Yankees led all of baseball with 930 runs, or 110 more than the Red Sox. Over the course of a full season, the Yanks averaged almost two-thirds of a run more than the Sox, not an insignificant margin.

Of course, offense doesn’t guarantee success. If it did, the Red Sox wouldn’t have gone 86 years between championships and the Detroit Tigers, who scored exactly two more runs over the course of the season than the Sox, wouldn’t have won the American League pennant.

But increasingly, for American League teams — especially those in the powerhouse A.L. East — a bludgeoning offense is a necessity, not a luxury.

So when the Red Sox took to overhauling their roster last winter, they knew improvements had to be made to the lineup. Accordingly, the team spent freely on Julio Lugo (four years, $38 million) and J.D. Drew (five years, $70 million), helping to fill holes, respectively, at the top and middle of the batting order.

Lugo provides some speed and athleticism at the top of the order, along with the ability to get on base (.340 lifetime on-base percentage). Lugo supplants Coco Crisp, who was installed in the leadoff spot last year, only to prove a poor match for the role.

Drew, in turn, takes over for Trot Nixon, who saw his power output drop precipitously in the last two years and had difficulty staying in the lineup.

Can the reconstituted Red Sox lineup again crack the 900-run barrier?

“I hope so,” said manager Terry Francona, who quickly amended his answer. “We’d better.”

Indeed, a punishing offense is essential in the Red Sox’ division, where the Yankees have perhaps the game’s most potent attack, and the Blue Jays, having added Frank Thomas to serve as their DH, aren’t slouches.

“They do it to you,” said Francona. “So you’d better be able to do it to them.”

The linchpin of the Sox’ offense, of course, is the dynamic duo of David Ortiz and Manny Ramirez, who have combined to hit no fewer than 84 homers and account for at least 239 RBI in each of the last three seasons. But beyond the sheer run-producing power of the two monsters in the middle, the Red Sox lineup this season looks to have both depth and a relentless approach. Red Sox hitters are adept at taking pitches and wearing down opposing staffs.

“Our guys have good approaches at the plate,” said new hitting coach Dave Magadan. “You’re not going to see too many one- and two-pitch at-bats. Grinding out those at-bats drives up the pitch count, and when you can get into the bullpen in the fourth and fifth inning, that’s a big thing.”

Thanks to the general paucity of pitching in the game, even the best staffs lack quality arms in long and middle relief. In addition, getting into the bullpen early can play a factor in a series, decimating an opponent.

While the majority of the damage will be done by the top five hitters in the order — Lugo, Kevin Youkilis, Ortiz, Ramirez and Drew — the Boston batting order is deep enough to ensure that pitchers can’t afford to let up at the bottom.

Mike Lowell enjoyed a bounce-back season with 20 homers and 80 RBI. Jason Varitek is expected to rebound from his worst year at the plate since becoming the Red Sox starting catcher in 1999. And Crisp, without the expectations that come from hitting leadoff and with his broken finger healed, could provide some spark from the No. 8 spot.

Only rookie Dustin Pedroia, tucked safely away in the ninth position, has yet to establish himself as a threat.

“There’s nowhere to hide with that lineup,” said a major-league advance scout. “If it’s not the best lineup in the game, it’s not far off. They’ve got a lot of smart hitters who know how to work pitchers and use the ballpark and the rest of the lineup to their advantage.”

Echoed Magadan: “There’s kind of a domino-like effect. Everybody needs some protection. You can’t pitch around everybody. We’ve got guys who aren’t afraid to take walks [even in an off-year, the Sox still led all A.L. teams by drawing 672 walks] and let the next guy do the damage.”

If the lineup bounces back to its usual production, Francona added, the pitching staff would be the beneficiary.

“When you’re scoring runs the way we were [in 2004-05],” the manager said, “it gives you a little more margin for error on the mound. It’s always easier to pitch with a lead.”

smcadam@projo.com