MESA, Ariz. -- When the A’s dealt Sonny Gray to the Yankees in 2017, they hauled in an undeniably talented trio. It seemed they had done well in reeling in James Kaprielian, Dustin Fowler and Jorge Mateo, even if they weren’t going to net big league production from any of them immediately.

The same is still true, yet the A’s have had to practice patience perhaps even more so than they thought originally.

Kaprielian, a former first-round Draft pick, can’t seem to shake the injury bug as he continues to work his way back from Tommy John surgery. Fowler also came to the A’s while rehabbing a serious injury -- an ugly collision in his big league debut led to an open patellar tendon repair in his right knee -- and the outfielder struggled at the plate upon his promotion to Oakland last year.

Mateo was limited to five Cactus League games last spring after nursing a left knee injury, then hit just .230 with a .280 on-base percentage in 131 games with Triple-A Nashville. Yet the long-hyped shortstop, prominently on display in big league camp this year, greatly impressed on both sides of the ball before being optioned to Triple-A on Sunday.

“I think he’s inspired by being at big league camp and getting an opportunity,” A’s manager Bob Melvin said. “You look at the numbers he put up last year and you look at his talent level, based on what we’ve seen, it’s like, how did that happen?

“But you understand over the course of 162 sometimes you get in some bad habits. But it’s been anything but from what we’ve seen in limited time last year and then he’s been fantastic, not only offensively but defensively.”

Mateo was signed by the Yankees at just 16 out of the Dominican Republic and almost immediately became their top prospect, bringing with him elite speed and a cannon of an arm -- skills that have allowed him to be versatile in the field. The knock has always been his bat; the value of his speed diminishes if he’s not on base. But the A’s are finally seeing signs of a different hitter -- a more patient hitter.

The 23-year-old has drawn three walks in 21 plate appearances this spring. He’s also totaled five hits, most recently picking up a single and scoring in Sunday’s affair with the Angels, to bring his spring average to .278.

“He’s an incredible talent,” Fowler said. “He’s always done well, and he’s always been the fastest guy on the field, but it looks like he’s starting to put it together hitting-wise. When that clicks, he’s going to be remarkable. He’s going to be special, and it’s going to be fun to see.”

Mateo mastered the Double-A level, which is often thought of as proving grounds for prospects, and now must show he can handle Triple-A pitching -- a different beast altogether, per Fowler, who said, “They know how to pitch, and you have to learn how to figure out pitchers and really how to hit.”

“It’s really different,” Mateo said. “You got different pitching, but you can learn from that so much. I think mentally it made me tougher. If something is going wrong, you have to learn how to deal with that, and I did.”

The A’s are well equipped to remain patient with Mateo, who is blocked at the big league level by Marcus Semien. They could later consider him as a utility option, much in the same way the Yankees once envisioned.

Ranked my MLB Pipeline as the team’s No. 8 prospect, Mateo is surely athletic enough to move around the field, and he could be a force off the bench. He has 259 stolen bases in 583 career Minor League games, 82 of them totaled in a single season (2015).

“He’s got all the tools,” Melvin said. “Once he figures it all out, he’s going to take off pretty quickly.”

“He shot up really quick and had a lot of hype on him in New York, and that’s tough to play behind sometimes,” Fowler said, “so it’s probably good for him to get over here and relax and do his thing.”