OAKLAND — The decision wasn’t one you would expect, not given the salary and the history of production.

But that’s how things are going with the Boston Red Sox’ J.D. Drew these days.

In a crucial spot in Monday night’s game, with Boston down to its last out, trailing by two runs and with a runner at third base, manager Terry Francona replaced his $70-million right fielder with a pinch-hitter.

It doesn’t matter who the pinch-hitter was (it was Jason Varitek), nor what he did in the at-bat (he blooped an RBI single, sparking the game-tying rally in what eventually turned out to be a 5-4 11-inning loss).

No, none of that really mattered. What did matter was that Francona wanted to win that game. That in itself, of course, is nothing new. He wants to win every game the Red Sox play, and to that end he manages to the best of his ability until the final out has been recorded. And on this night, he didn’t think Drew could help the Sox win, not in that situation.

Francona’s decision spoke volumes about what he can — and more importantly, what he can’t — expect from Drew, the free-agent who opted out of his contract with the Los Angeles Dodgers and signed a lucrative deal with Boston, replacing popular, home-grown Trot Nixon, whom the Red Sox let walk away via free agency.

Drew, a left-handed hitter, was not in the starting lineup last night and may not be in there tonight, with Oakland starting a left-hander both games. When last night’s game began, Drew was batting a mere .224 with a paltry two home runs and 17 RBI in 161 at-bats.

Francona tried to rationalize his Monday night move, choosing his words carefully, not putting down Drew, consistent in his philosophy to never criticize a player in the media.

He lifted Drew against left-hander Alan Embree for several reasons, said Francona.

“I don’t think there’s a manager who likes to pinch-hit (for a starter, such as Drew), but we pinch-hit for (utility player Alex) Cora, too,” said Francona yesterday during his daily media briefing.

“I don’t take pleasure in that. I was pinch-hit for a lot as a player. That’s why you always try to tell a guy ahead of time (about the move). But you have to play the game. J.D. is struggling. Jason (a switch-hitter) is such a good right-handed hitter (against lefties) and he was available, which he isn’t most of the time (because he catches regularly) and we had Coco (Crisp, as a pinch-running option) on the bench. You know what, it’s worth a shot there. It helped us,” said Francona.

These days it is Drew who needs the help. Since beginning the season red-hot — batting .357 (20-for-56) over his first 16 games — Drew has slumped badly, batting a woeful .152 (16-for-105). His power numbers? Over that stretch, which began on April 23, Drew has three doubles, one triple, no homers and has driven in only nine runs despite having Kevin Youkilis, David Ortiz and Manny Ramirez hitting directly in front of him.

And while every hitter goes through times when he hits the ball hard and gets few results to show for it, that is by no means the case with Drew.

He rarely drives the ball to the outfield. Drew was expected to take advantage of the wall in left and left-center, but the Green Monster isn’t exactly fearful of suffering another dent when Drew steps into the batter’s box.

Drew has become the rollover king, rolling over on pitches and generating weak and routine ground balls to the right side.

Maybe he’s hurt. He did miss several games last week because of a tight right hamstring. Maybe he’s more hurt than he’s letting on because he doesn’t want to play into his reputation as a soft player who spends too much time on the disabled list to reach his production potential. Maybe it’s also the $70 million over five years, the sum lavished on him by the Red Sox that he has yet to really earn.

His troubles have flown under the radar with Boston boasting a 37-19 record, the best in baseball.

But when you’re J.D. Drew, making a lot of money to produce in the clutch, and you get pinch-hit for with two outs in the ninth inning, it’s a statement that right now he is not living up to his potential or his salary, and there’s no hiding that from the team.

skrasner@projo.com