J.J. Watt Raves Over Taylor Swift In Epic 'The Eras Tour' Show Breakdown

J.J. Watt has apparently turned into a music critic in retirement ... and Taylor Swift has passed his first assignment -- with the ex-NFL star absolutely raving over her following her shows in AZ over the weekend.

The former Cardinals pass rusher hit Saturday's "The Eras Tour" concert at State Farm Stadium in Glendale, AZ with his wife and friends ... and in a full breakdown of Swift's performance the next day, he said he was blown away by what he saw.

In a 2:38 review that Watt posted on his social media pages, he gushed over Swift ... saying everything from the song choices to the outfits to the production had him in awe.

"First off," he said, "unbelievable."

Watt was floored by Swift's ability to rattle off 44 songs in 3-plus hours -- while never pausing for much longer than a few minutes.

"There was no intermission," he said. "There was no halftime. There was no TV timeouts."

"She crushed it," he added.

The show seemed to surprise the 33-year-old -- who just retired from the NFL in January -- as he joked before the concert on his wife's Instagram page, "Everyone send me your best wishes. Thank you."

Watt revealed he even grabbed a Taylor hoodie after the show!!!

"It was impressive to witness," he said. "And I did walk out with some merch. So, Swiftie life!"