What will the Red Sox’ catching corps look like in the future?

Catcher Connor Wong has won the trust of pitchers — most notably Nate Eovaldi, with whom he works out in the winter and been paired in multiple big league starts.Jim Davis/Globe Staff

Uncertainty hovers over the future of the Red Sox catching corps.

Longtime mainstay Christian Vázquez and backup Kevin Plawecki are approaching free agency following the season. (According to a major league source, the Sox have not had recent discussions with Vázquez about an extension.) Their status and how the Sox decide to proceed is tied to a question: Do they have a minor league option ready to join the big leagues?

The answer is complicated by the unique nature of the position. Catchers’ responsibilities are more varied than those of any other position, helping to explain the typically deliberate development path catchers must follow to the majors.

Consider the transition that Nathan Hickey, a fifth-round selection by the Red Sox in last year’s draft out of the University of Florida who spent the first 2½ months with Single A Salem before a recent promotion to High A Greenville, has made in his first full pro season.

Hickey was an infielder in high school who moved behind the plate in college to get his bat in the lineup. Some organizations questioned whether he’d stick at the demanding position, a perception he was eager to dispel.

“That didn’t really sit well with me,” said Hickey. “I just hadn’t had enough time behind the plate to be able to show that was the spot for me. But I learned in one day more things about catching being here with Boston than I ever did at Florida.”

That crash course includes responsibilities as a catcher that are vastly different from those he had in college.

At Florida, his coach called the pitches. Hickey viewed his chief responsibility as being what he did with a bat in his hands.

Now, while he has above-average offensive potential for the position, he’s retrained his outlook to focus on his work with pitchers and to learn to study and absorb a game plan, and then how to veer from it based on how his pitchers and opposing hitters look.

“It was a big step. Pitch-calling was kind of the thing that was stumping me a little bit at the beginning [of the season],” said Hickey, who is hitting .270/.413/.509 with eight homers in 46 games. “But [being a catcher] is not really [about] me being successful, it’s making [the pitcher] look as successful as you can.”

Hickey is years from being part of the Sox’ big league catching equation. In Triple A Worcester, however, the Sox have two catchers in Connor Wong (acquired in the Mookie Betts trade) and Ronaldo Hernández (acquired in a trade from the Rays for Jeffrey Springs) who are trying to assert themselves as part of the team’s future.

The undertaking got off to an ominous start this year. As much as defense dictates catching jobs in the big leagues, through mid-May there were concerns about whether Wong and Hernández were falling short of the minimum offensive threshold needed to play at the next level.

Wong hit .167/.254/.183 with a 22.4 percent strikeout rate through 16 games. Hernández to roughly the same point was hitting .122/.133/.207 with 28 strikeouts and just one walk.

Both have since experienced startling turnarounds. Wong is hitting .313/.380/.493 with five homers in his last 37 games. Hernández has posted a gaudy .383/.403/.624 line with seven homers in his last 36 contests, cutting his strikeout rate to 13.3 percent.

“I’m baffled,” WooSox manager Chad Tracy acknowledged. “It’s a remarkable turnaround.”

Assistant WooSox hitting coach Mike Montville credited improved pitch selection and more frequent damage against pitches in the strike zone as being at the heart of the players’ jumps. He also worked with both players early in the year on their pre-swing mechanics and timing so they could have more time to work through the strike zone with their swings.

The results have been profound. Still, Wong and Hernández recognize that their offense is a secondary element in determining their potential fit for the big league roster.

“Every year I’m trying to get better with my defense. That’s my priority,” said Hernández. “I don’t care every day if I’m getting base hits. My priority is the pitcher.”

“It’s taken thousands and thousands of pitches,” said Wong. “But the more pitches I’ve seen, I feel like the more comfortable I’ve gotten.”

Like Hickey, Wong’s games were mostly called by his coaching staff at the University of Houston, though he was permitted at the end of his junior year to start calling games once a week. He then got a crash course in his early professional seasons with the Dodgers.

Wong came to the Sox as a player whose athleticism behind the plate and potential for versatility (he also played second and third in the Dodgers system) stood out. Offensively, he showed power potential (24 homers in 2019) with a high strikeout rate.

Now, he shows a line drive, gap-to-gap approach, has cut down on his strikeouts, and most importantly, has won the trust of pitchers — most notably Nate Eovaldi, with whom he works out in the winter and been paired in multiple big league starts.

Tracy said that Wong grades among the top Triple A catchers in pitch-framing and presentation, though Wong’s focus is on ensuring that pitches in the zone are indeed called strikes rather than stealing them.

Hernández, meanwhile, has made his own defensive strides. As a larger catcher (6 feet 1 inch, 230 pounds), he struggled earlier this year but has become comfortable with a one-knee stance and with a more bent posture at the waist to do a better job of receiving pitches in different parts of the zone, particularly the bottom.

Wong, 26, and Hernández, 24, are steadily improving on both sides of the ball. The deliberate nature of those improvements is intrinsic to their position. But the fact that both continue to advance gives the Sox potential directions as they move forward.

“I do think we have some young catchers here that have a chance to be impactful, no doubt,” said Tracy. “I am confident that the way they’re both improving, they’re putting themselves in the conversation at least.”

Three up

▪ Top prospect Marcelo Mayer has rebounded from a mid-June slump with one of his best stretches of the year. Over his last nine games for Single A Salem entering Thursday, Mayer was hitting .417/.533/.833 with three homers and nine extra-base hits along with three steals. He’s hitting .294/.386/.527 with seven homers for the year.

▪ Righthander Hunter Dobbins, who was coming off of Tommy John surgery when the Red Sox took him in the eighth round last year, completed his rehab in June and has been impressive over six appearances with Salem. In his last four starts, he has a 1.59 ERA and a 20-to-2 strikeout to-walk ratio. His four-pitch mix includes a fastball that has topped out at 97 miles per hour.

▪ First baseman Pedro Castellanos, 24, started slowly but has been one of the top performers in the Sox system since early May. Over 50 games from May 6 through July 6 with Double A Portland and more recently with Triple A Worcester, Castellanos is hitting .352/.370/.583 with nine homers and 27 extra-base hits.

Three down

▪ Lefthander Brandon Walter remains in Fort Myers, Fla., a month after he was shut down in Worcester because of a neck injury. He has yet to resume throwing, but the team is hopeful that he will soon. Walter has a 3.59 ERA with a 75-to-7 strikeout-to-walk ratio in 57⅔ innings this year.

▪ Super-utility prospect Eddinson Paulino has seen his impressive production take a hit. In 13 games entering Thursday, the 20-year-old was hitting .132/.242/.283 with 14 strikeouts in 62 plate appearances — a turn from the eye-opening .357/.471/.696 line he posted over the preceding 14-game stretch in early June.

▪ Outfielder Nick Decker entered Thursday amid an 0-for-22 slump that included 15 strikeouts for High A Greenville. The 22-year-old, once viewed as a prospect who combined power and defensive potential, is hitting .127 with a .291 OBP and .268 slugging mark with a 39.8 percent strikeout rate.