Another day, another Yankees injury setback.

And this one might hurt the most.

Luis Severino has been shut down because of soreness in his right lat, manager Aaron Boone revealed to reporters before the Yankees faced the Red Sox on Saturday in London.

“He re-MRI’d, which is what we wanted to do before he got back on the mound,” Boone said. “He’s about 90 percent healed, so we kind of slowed it down.”

Boone said his club’s ace will only throw off the mound once he’s fully recovered, which he expects to take seven-to-10 days.

GM Brian Cashman had previously said Severino might not return until after the All-Star break in mid-July. That now seems like a reach.

“It just makes me wonder, obviously, when we’re going to get the lat right,” Cashman said Saturday.

Severino was originally shut down before the season with rotator-cuff inflammation, though an MRI exam later showed a more severe Grade 2 lat strain. Severino’s unclear future has pushed the Yankees to survey the trade market for another arm.

Reliever Dellin Betances, whose shoulder has also trapped him on the injured list since spring training, is expected to resume throwing when the Yankees come back from London this coming week