Over the last two seasons, David Ortiz has gotten a free pass. In 2008, his campaign was derailed by injuries; in 2009, he was plagued by family issues, a steroid scandal and generally poor performance. But fans, and his club, were generally forgiving, happy to let Ortiz live off the credit he built up while leading Boston to two World Series victories.

No more. Management expects that, with one year left in his contract, Ortiz must return to (most) of his menacing old self or there's a good chance the team will find another option at DH when his contract expires after next season.

"If he's going to be the DH on this team, we need him to be a force. We're a different team when he is that force," general manager Theo Epstein said earlier this week.

In that respect, this will be an important winter, and then season, for the Boston slugger, who turns 34 next month and has a team option for 2011.

"There will be conversations about what he thinks he needs to do to get back there. But it's important. It's important for this club for him to be that force as the DH."

For much of this season, Ortiz was not that force. His final numbers were decent: he hit .238 with 28 home runs and 99 RBI while still walking enough times (81) to amass an acceptable .332 on-base percentage.

But the numbers came in an unorthodox and uneven fashion. As of June 1, Ortiz had one home run and 17 RBI. His batting average was hovering around .200. There seemed to be no way he would ever pull himself out of his funk.

In Seattle, manager Terry Francona benched Ortiz for the weekend, hoping that would help the slugger clear his head. He was also dropped down in the batting order, briefly to sixth and seventh, but generally to fifth. His customary third spot in the lineup went to Kevin Youkilis, and later to Victor Martinez.

Then, amazingly, Ortiz bounced back, morphing into one of the biggest hitters in baseball over the final four months of the regular season.

Epstein seemed hesitant to describe what he expects from Ortiz going forward. It seems clear that next year will be a defining season for the Red Sox slugger, and is likely to determine whether the club will pick up his 2011 option or turn to someone else.

"I think the last four months of the season were certainly better than the first two months for him," Epstein said.

"If he can find a way to prepare himself for this season where he can build off what he did from about June 1 on and grow from there?" Epstein trailed off.

At one time, Ortiz provided enough power and on-base ability that his shortcomings on the field could be easily overlooked. From 2004 to 2007, Ortiz hit at least 44 home runs and walked 100 times each year.

But when he's no longer mashing at that level, Ortiz is difficult to build around. As a DH who can barely play one other position — first base — Ortiz severely limits his club's flexibility, and valuable roster spots must be devoted to keeping his hit-only bat available.

The 14 American League teams got an average of a .255 batting average, 69 walks, 28 home runs and 89 RBI out of their DH positions. The team-dependent RBI aside, that's about what Ortiz offered his team this season. But what will he be when his contract expires after next season? It took a Herculean effort for Ortiz to bring his numbers back to that average point, and the Red Sox have three other players –– Youkilis, Martinez and Casey Kotchman –– who might get regular playing time at first base. After 2010, will an aging Ortiz be worth it?

Ortiz signed a four-year, $52-million deal in 2007 that pays him $12.5 million per year. The deal has a $12.5-million option for 2011. The way Epstein talked, it seems reasonable to assume that the team would pick up that option only if Ortiz boosts his production back to at least near his 2008 levels, when he hit 34 home runs, scored 116 runs and drove in 117 while hitting .332 with an impressive .445 on-base percentage.

That doesn't seem too far-fetched. After this season ended, Ortiz said he'll take the lessons he learned this year and apply them to next year. But he won't think about this season much, he vowed.

"I don't think about anything. That's in the past already. Next year is going to be next year. You've just got to come ready to play," Ortiz said.

As soon as he turned the corner, and his hitting came together in the summer months, he never looked back, he said –– even while dealing with the revelations that his name was on a list of 104 players who tested positive for banned substances in 2003.

"Oh, it's already behind me, believe me. It's already behind me. I don't deal with negative stuff too much, anything like that. Even after my first two months, I put them in the past. There's nothing I can –– what good can I get from that?" Ortiz said.

That may be the right attitude, and Ortiz's performance over the final four months of the season was impressive.

But when his team needed him most, Ortiz was invisible.

Ortiz absolutely disappeared in the 2009 playoffs, going 1-for-12 with no walks despite facing two right-handed pitchers in John Lackey and Jered Weaver.

Ortiz made his name in the 2003 and '04 postseasons, delivering clutch hits game after game. But his batting averages have fallen in his last three postseason series: .235 in the 2008 ALDS, .154 in the 2008 ALCS and .083 this season.

Ortiz likely will have a chance to make up for that in 2010, but to reclaim his place in postseason lore, Ortiz must first prove he can still do it over a full regular season.

dbarbari@projo.com