BOSTON — When you wish upon a star, makes no difference who you are. Anything your heart desires will come to you.

Unless you’re the Yankees and your wish concerns the Red Sox’s bullpen. Then you get no guarantees.

Here in Red Sox Nation, folks fretted about their club’s failure to add an arm to their weakest unit, or at least to their department that trails the Yankees by the largest margin, by Tuesday’s non-waiver trade deadline. Which would make more sense if the Red Sox were showing any tangible sign of being hindered by their current relief corps.

“The first week of the season it gets magnified, and the trading deadline: Whatever you do wrong, you can’t do, so all of a sudden you need to get somebody,” Boston manager Alex Cora said Thursday, before the Red Sox and Yankees resumed their rivalry at Fenway Park. “We’re very comfortable with our bullpen.”

These clubs’ most recent meeting came July 1 at Yankee Stadium, when the Yankees pounded David Price and three relievers to the tune of an 11-1 blowout victory. The polarizing Price took the brunt of the beating, giving up eight runs in 3 ¹/₃ innings. Bullpen guys Justin Haley, Brandon Workman and Hector Velazquez teamed to permit three runs in 4 ²/₃ innings.

That victory pulled the Yankees even with the Red Sox atop the American League East and actually put Aaron Boone’s group up by two games in the loss column. In the month that followed, the Sawx posted a 19-5 record to the Yankees’ 14-11, jumping back ahead by five and a half games, four in the loss column.

So really, how big an Achilles heel can this Red Sox bullpen be?

As per FanGraphs, the Yankees led the AL with 6.9 bullpen wins above replacement, followed by the Astros (5.0) and the Red Sox (4.9). AL starting pitchers’ WAR looked like this: Astros 15.7, Indians 14.4, Red Sox 11.9, Yankees 9.0.

So the Red Sox’s starters and relievers ranked the same — very high — and hence they placed second overall at 16.8, behind the Astros’ 20.7 and ahead of the Yankees’ 15.9.

“The way they threw the ball against Philly, that was good to see,” Cora said, referring to his club’s two-game split against the Phillies this week. “I think Ryan [Brasier], he’s done an outstanding job for us since he’s been called up. He’s another arm that we can rely on. Joe [Kelly], he’s done well the two days against Philly.

“We feel good. I love the feedback from the opposition, talking to some of the hitters. ‘OK, we have good arms.’ ”

Kelly, who made himself known to Yankees fans back in April when he drilled the now-traded Tyler Austin with a pitch, recorded back-to-back shutout innings against the Phillies. His struggles of late had set off the most alarms. Brasier, a 30-year-old right-hander who had last pitched in the majors for the 2013 Angels, put up a 0.90 ERA in his first nine appearances totaling 10 innings, although his 1.75 strikeouts-to-walks ratio threatens some regression.

Velazquez and his fellow right-handers Matt Barnes and Heath Hembree have pitched well, and of course there’s elite closer Craig Kimbrel.

The top concern has to be not the relievers, but rather ace Chris Sale, who will miss this series while rehabilitating an ailing left shoulder that the Red Sox hope will be a short-term thing. It figures to be easier to add a reliever than a starter this month, when players must clear waivers in order to be traded to any team.

Asked about the Yankees strengthening their strength with the trade for Zach Britton, Cora said: “They still have a good bullpen. We still have to get to the starters. I think we’ve done a good job throughout the year of getting leads and maintaining leads.”

That they have. It seems awfully optimistic to prophesy a Red Sox crash-and-burn based on something they didn’t do when they have done so much right already.