ANAHEIM, Calif. — J.D. Drew was in center field last night for the first time this season, a season that has seen him occupy center stage — for all the wrong reasons.

Signed as a free agent last winter to a $70-million, five-year deal, Drew has been an enigma — a likable sort with immense talent who seemingly never fails to dash expectations.

One prominent, longtime scout who watched Drew often at Florida State called him the most talented baseball player he had ever seen. But now in his 10th major-league season — and fourth team — Drew remains a chronic underachiever.

Heading into last night, Drew was hitting .251 with six homers and 41 RBI — respectable numbers for a role player, but hardly what’s expected from a player drawing a $14-million annual salary.

What’s most stunning is his lack of extra-base power. With 27 extra-base hits, he ranks eighth on the Sox. His anemic .378 slugging percentage ranks him behind Alex Cora. (.405) and his six homers are just one more than Doug Mirabelli’s output, despite having 222 more at-bats than the Sox’ backup catcher.

When the Sox lavished him with the deal, enticing him to opt out of a lucrative, long-term deal with the Los Angeles Dodgers, it was with full knowledge that Drew had earned a reputation as a passive player with a history of frequent absences from the lineup.

In a stat cited often during last winter, it was noted that only twice in his first nine seasons had Drew played as many 140 games. Having already missed 17 game through the first 114, Drew would need to play 43 of the remaining 48 games to top that mark this season, a highly unlikely proposition.

To be fair, most of Drew’s absences this season have not been injury-related. But the very fact that manager Terry Francona feels uncomfortable playing Drew against many left-handers is an indictment of another sort. Shouldn’t a player of Drew’s stature — and salary — be more than a platoon player?

Unfortunately for the Red Sox, the answer may be no. Drew went into last night hitting a mere .215 against lefties this season. His OPS (on-base percentage plus slugging percentage) was a lackluster .634.

According to numerous talent evaluators, Drew fell into some bad habits at the plate early in the season, causing his average to dip and his production to stagnate. Then, just when his began to get hot at the plate, he was understandably distracted by his 17-month-old son’s medical complications, which eventually resulted in surgery.

Team sources indicate that his son’s illness wore heavily on Drew, who is intensely religious and devoted to his family. Private and quiet by nature, Drew withdrew further in recent weeks, burdened by his son’s health issues.

Any suggestion that Drew’s switch in leagues — this is first in the American League — is the reason for his mediocre play seems misplaced. Unlike a decade ago, when the National League was more of a fastball league, the differences between the two now are blurred, thanks to interleague play, player movement and uniform umpiring crews.

Red Sox officials remain mystified by his inability — refusal? — to use Fenway Park’s left-field wall, as great left-handed hitters like Fred Lynn, Wade Boggs and so many others have done to their advantage. With more than two-thirds of the season complete, Drew has hit just three balls off The Wall.

Instead, Drew seems to habitually roll over on pitches, frequently resulting in groundouts to second base.

In his few flashes of great play this season, Drew seems to have been stimulated by personal motivation. He performed brilliantly in an interleague series against Arizona, most agree, thanks to a fraternal rivalry with younger brother Stephen, the Diamondbacks’ young shortstop. And he erupted in Atlanta, it’s believed, out of a desire to prove a point to the Braves, who chose not to re-sign him after his one season there.

(Drew’s history of enjoying big games in Philadelphia, where he’s vilified for having spurned the team which originally drafted him, is further evidence of this).

When they signed Drew, club officials cited his ability to tune out external forces like fan reaction and media criticism. But less than one full season into what now looks like a long five-year deal, that hardly seem re-assuring.

smcadam@projo.com