Joe GirardiBOSTON — Joe Girardi is a weary man.

For all the honorary badges he could accept for taking a team that by all signs should be putting up a losing season and instead cajoling it to a 79-70 record with a chance at a playoff berth, he’s still gunning for a postseason trophy of some sort, even if it’s just a wild card ticket.

Girardi has managed his team through dozens of injuries, including season-ending blows to the club’s biggest stars and losing both the starter and the backup at some positions. He’s watched the Yankees stay afloat even as their starting pitching falters and their bullpen — the whole baker’s dozen of relief arms that New York has called from all reaches of its farm system — continues to struggle.

But what has to be most perplexing for Girardi is not CC Sabathia’s drop-off this season, the Yankees’ record despite their run differential this year or how they lose a player for every game they get closer in the wild card race (the most recent being Brett Gardner, who is likely out for the rest of the season).

The weirdest wrinkle has to be how the Yankees just can’t do a thing against the Red Sox.

The Yankees have lost seven games in September. Five have been against Boston. The Yankees have a .530 winning percentage this year, but they are 6-12 when playing Boston. The Yankees scored 25 runs in the first three games of their series with the Red Sox last week but lost each game, and the only consolation in this Saturday’s 5-1 loss was that the Yankees didn’t waste a four-run comeback effort, which they did in Friday night’s defeat.

“They have,” Girardi said when asked Saturday whether the Red Sox have been playing well. “They scored a ton of runs on us at our place, and today was the second-fewest runs we’ve hit in seven games. They’re swinging the bats extremely well, and then they went to Tampa and played well — I mean, they’re playing really well. But, we come off a series in Baltimore where we played extremely well, too.”

For as much as the Yankees have perennially tormented the rest of the league, Boston has returned the favor this season. The Yankees swept the White Sox before the Red Sox pounded them back into place last week, and New York took three out of four games from the Orioles this week before the Sox again trimmed their sails Friday and Saturday.

The Red Sox have showed no letup in the final stretch of this season, with everyone from the resurgent Mike Napoli to the perfect Koji Uehara helping Boston produce dominating wins as the playoffs approach.

While the Red Sox aim to clinch the American League East going away, it’s especially frustrating for a Yankees team that’s hung around all season to not be able to get anything done against its division rival.

“It’s only a must-win when it’s an elimination game, but I think it’s a real important game,” Girardi said of Sunday’s series finale.

Girardi was asked about the Yankees’ view of the Red Sox after Alex Rodriguez, who has been working from the designated hitter spot against Boston while dealing with a balky hamstring, complimented the Red Sox on Friday.

“Let me tell you something. They got a very good team over there,” he said, according to Newsday. “This is a hard team to measure yourself against right now.”

Girardi steered the conversation away from the Red Sox on Saturday.

“I worry more about our team than the other team, and how we play, than how we measure or not measure — we have to go out and win games,” he said.

He also wasn’t letting injuries be the scapegoat, despite Alfonso Soriano getting scratched from the lineup right before Saturday’s game began and Gardner likely being lost for the season.

“We’ve lost a couple guys recently,” he said. “You know, I don’t think Soriano’s going to be real long-term. Gardner is a different story — you lose your lead-off hitter. [Curtis Granderson has] done a pretty good job in his absence, but obviously, it shrinks your lineup a little when you have to take someone out. But it’s no excuse. I mean, you’re still major league hitters, and you have to figure it out.”

The Yankees’ major league hitters, however, have not been able to do much against the Red Sox’ major leaguers in their last six meetings. That was the reality that was heavy around Girardi’s calm but tired voice on Saturday.

“If they say they’re able, I’m gonna play [the injured players]. I think you have to,” said the manager, who has been filling out his team with farmhands and emergency trades all season. “You can’t take for granted one game.”

Even if the Yankees wish the Red Sox would, just once this season.