FORT MYERS, Fla. — For most of the offseason, Adrian Gonzalez and Carl Crawford assumed primacy in the rapidly escalating expectations for the Red Sox. Those two provided answers to team needs. But two returning players who loom as question marks may be just as significant.

On Thursday morning, Josh Beckett and John Lackey strolled out of the Sox clubhouse, taking the first steps in what the Sox hope — perhaps even need — to be a year in which they will rebound significantly.

Lackey, of course, struggled to live up to his billing as a top-of-the-rotation starter after coming over on a five-year, $82.5 million deal he signed as a free agent — at the time, the largest contract ever given out by the current Sox ownership group. His 14-11 record and 4.40 ERA at the end of the year were solid, but short of dominant.

Even so, the performance wasn’t alarming to the Sox. The pitcher faced the external challenges of a transition to a new team and division, and the pressure of expectations in doing so. He was healthy for the full season, making 33 starts and pitching a team-leading 215 innings.

Moreover, despite a 5-6 record in the second half, he posted strong numbers: A 3.97 ERA, 7.8 strikeouts per nine innings, a 3.4 strikeout-to-walk rate and a 1.22 WHIP — numbers that stacked up well against his career totals. “John had a better second half than first half,” general manager Theo Epstein noted Thursday. “That’s a sign that he adjusted to his new surroundings in the American League East, and I look forward to a typical John Lackey season.”

Beckett, however, is another matter. There is little solace to be gleaned from any stretch of the season, whether his injury-impaired first half or a second half during which he continued to be tagged. He finished the year having pitched just 127 2/3 innings in 21 starts with a 5.78 ERA.

Of the 147 pitchers who threw at least 100 innings last year, Beckett had the fifth-worst ERA. Opponents had an .848 OPS against him, sixth worst in the majors. Overall, opponents crushed him for a .292 average, .354 OBP and .492 slugging mark.

In many respects, the best things that could have been said about Beckett’s 2010 season were A) that it’s over and B) he took full responsibility for it.

“Josh certainly can do better than he did last year and he knows that,” Epstein said. “It looks like he went out and had a really strong winter, getting in great shape. The big thing is he didn’t hide from the year he had. He took accountability for it. He knows there’s more in there. I wouldn’t bet against him at all.”

Of course, Epstein has little choice in the matter. After all, the Sox made the decision last spring to sign Beckett to a four-year, $72 million extension that begins with the 2011 season. Clearly, the Sox made their bet on Beckett in early 2010, not against him.

But is it realistic to think that the right-hander can bounce back from his depths of 2010? Does history offer grounds for optimism that the right-hander, in his age 31 season, can re-emerge as a reliable pitcher capable of performing at or near an All-Star level? Or was there anything that could offer glimpses of hope from his 2010 season?

WHAT HISTORY SAYS

In the context of 2010 and baseball history, Beckett’s season was abysmal. Boston Herald colleague John Tomase recently examined the history of pitchers at the age of 30 and later who suffered a season like Beckett’s — at least 125 innings, a 5.75 ERA or worse — and noted that of the 66 pitchers who turned in such seasons, all but three were virtually done as effective starters.

The claim was eye-opening, and it suggests that the Sox have every reason to be terrified that their deal with Beckett soon could become an albatross.

That said, one can get a slightly different view of the pitcher’s prospects by changing slightly the pitchers to whom he is being compared. Given that one expects precipitous declines for pitchers as they age, it seems unfair to compare a 30-year-old Beckett to a 39-year-old Al Leiter. Beckett was ostensibly in the middle of his prime last year, rather than well past it.

Moreover, the 125-inning threshold and 5.75 ERA threshold are both somewhat arbitrary. If a pitcher has a terrible, injury-riddled year, an 80-inning season with a 6.00 ERA should probably raise as many red flags as Beckett’s season.

So, suppose one looks at Beckett in the context of starting pitchers in their primes (ages 28-32) who had an ERA+ that was 20 percent or more below league average, and who, in the era of the 162-game schedule, threw at least half a season (81+ innings) but fewer than 162 innings (thereby helping to narrow the field to include pitchers who were dealing with injuries).

Through the 2009 season, there were 64 pitchers who fit into that category. Almost none had Beckett’s pedigree as a top-of-the-rotation pitcher, a reminder of how truly shocking his 2010 flop was.

There were several examples of pitchers who recovered to have at least moderate success after a Beckett-sized flop. Pitchers like Brad Penny, Vicente Padilla and others performed at or near league average in subsequent years. Jim DeShaies had a bad age 31 year, but recovered for a couple seasons as a slightly better-than-average starter. Some, such as Julian Tavarez and Darren Oliver, were shifted to the bullpen and found success there.

Some hurlers were glimpsing the beginning of an injury-riddled end. Mark Mulder, for instance, had a 7.14 ERA over 17 starts as a 28-year-old in 2006. That was basically it for the left-hander, who made just six more appearances over the next two years before retiring.

But there are some noteworthy cases of pitchers who rebounded in spectacular fashion. At the top of the list is Cliff Lee, who went 5-8 with a 6.29 ERA for the Indians in 2007 at age 28. Since then? A Cy Young award, a 48-25 record and 2.98 ERA in the last three seasons.

There are other noteworthy cases that could offer Beckett grounds for optimism. Paul Byrd, for instance, was an All-Star in 1999, suffered a brutal down/injury year in 2000, then had an ERA of 3.94 (ERA+ of 117) over his next four seasons.

Juan Guzman suffered dismal seasons with the Blue Jays as a 27- and 28-year-old but rebounded to lead the AL in ERA at age 29, the first of a few more seasons as an above-average starter.

Mike Scott was 5-11 with a 4.68 ERA (ERA+ of 71) as a 29-year-old, then commenced a four-year run in which he was 86-49 with a 2.93 ERA (121 ERA+) in the next four years, which included a Cy Young season.

John Smiley had a dreadful, injury-riddled age 28 season in 1993, then performed at an All-Star level over his next three seasons. Mark Gubicza recovered from poor age 27 and 28 seasons to resume life as a very effective starter for the Royals. Combustible Braves starter Pascual Perez went 1-13 with a 6.14 ERA (62 ERA+) as a 28-year-old, missed all of his age 29 season, then had a 2.80 ERA (131 ERA+) from ages 30-32.

There are some other fascinating examples of players who recovered from injury-riddled disasters to regain dominance. Hall of Famer Lefty Grove, for instance, had an 8-8 record and 6.50 ERA in 109 innings as a 34-year-old in his first season with the Sox (after a trade from the A’s). But Grove didn’t just bounce back — he led the AL in ERA in four of the next five years, cementing his Cooperstown credentials.

So, that sample set would suggest that there’s a small but important set of pitchers who have recovered from miserable seasons in their primes to achieve either effectiveness or even dominance. For pitchers with Beckett’s record — multiple All-Star appearances, consideration as a top Cy Young candidate — there are more cases of rebounds than downward spirals following years such as the one that he turned in.

ANOTHER LOOK AT 2010, AND FORECASTING 2011

But was there evidence last season to suggest an actual reason why Beckett should be able to exist as one of the pitchers capable of bouncing back?

One can certainly make that case by looking beyond that hideous ERA. Here are a few numbers of note for Beckett in 2010:

— Opponents swung and missed at 8.4 percent of his pitches in 2010, compared to 8.3 percent of his pitches in 2008 and 2009. He still has swing-and-miss stuff.

— Further evidence of that notion: Beckett had 8.2 strikeouts per nine innings last year, third most ever by a pitcher age 28 or older with an ERA+ that was 80 or below. That was only slightly below his career average of 8.5 strikeouts per nine. That further underscores the notion that his stuff separated him from others on the list of infamy.

— His batting average on balls in play was .341, one of the worst marks among pitchers to produce such a brutal ERA. It was easily the worst BABIP of Beckett’s career, almost 50 points worse than the career .294 mark he had through 2009. The mark was also drastically different than the .295 BABIP by the Red Sox pitching staff and the .293 league average.

BABIP is influenced heavily by defense and luck. Pitchers have little control over it. When there’s a significant divergence — as there was for Beckett in 2010 — the expectation should be that the pitcher will move back toward his career norms.

That helps to explain why some of the more advanced statistics — which are meant to account for fluctuations of luck on balls in play and the rate of fly balls clearing the fence for homers — are quite optimistic about Beckett. It also helps to explain why projection systems such as those used in the Bill James Handbook by Baseball Information Solution anticipate a big bounceback for Beckett, with a forecast of a sub-4.00 ERA.

— Those are all reasons for optimism about Beckett’s prospects of rebounding. That said, there are some elements that suggest caution about the pitcher’s future. For instance, his fastball velocity has slipped gradually but steadily since his first year with the Sox, going from 94.7 mph in 2006 to 94.6 mph in 2007, 94.3 mph in both 2008 and 2009 and then falling to 93.5 mph last year.

— Perhaps because of the decline in velocity, he has also showed diminished trust in the pitch. In 2008, according to Fangraphs.com, his fastball was his offering of choice on 66.9 percent of his pitches; that fell to 60.2 percent in 2009 and just 55.2 percent of his pitches in 2010.

CHOOSING TO FORGET

Beckett’s 2010 season was a jarring aberration from his career to that point, both for the pitcher and the Red Sox. And so, the Sox are putting faith in the idea that the glaring, blaring numbers of 2010 did not accurately represent the right-hander.

He has been the team’s Opening Day starter in the last two seasons as well as a key part of the team’s postseason blueprint for success. He remains a huge part of the Sox’ hopes going forward. As significant as the team’s offseason lineup upgrades have been, the performance of the rotation will be at least as significant in determining where the team will end up in the coming season, and Beckett will play an immense role in seeing how closely ambitions and outcomes can align.

All of that means that the Sox are not just hopeful for a bounceback — they will need it. As such, they are engaging in an act of selective memory in hoping that they will get the Beckett of 2007-09, rather than the pitcher whose results fell far short of that standard in 2010.

“We’re for the most part throwing out last year and relying on the greater body of evidence for how we project him going forward,” Epstein said during the offseason. “It’s very important. We’re a different starting rotation with him being anywhere close to what he’s been throughout his career. He’s going to get the ball, and he’s going to pitch big games, and big innings and get big outs for us. So having him be his normal, effective self will mean a lot to this club.”