THETFORD — Baseball has been at the core of Mason and Boone Fahey’s relationship for years.

A junior and sophomore, respectively, at Thetford Academy, the Faheys are always talking baseball, whether it’s their own games, college ball or their beloved Boston Red Sox. The sister and brother began this spring as the Panthers’ starting battery. With Boone as the ace pitcher and Mason catching for him, Thetford looked primed for another deep run in the VPA Division III playoffs.

But as the postseason opened for the Panthers on Tuesday, neither Fahey was on the field. They had both handed in their uniforms the previous Friday as Mason had grown increasingly frustrated with coach Phil Chaput diminishing her playing time. She had started behind the plate to open the season, then was moved to first base because of an injury to the starter there, and eventually was removed from the starting lineup entirely.

“It’s something that no one wants to say, and frankly I don’t want to say it because I don’t want to believe it,” Boone said. “But the only reason I can come to why Mason doesn’t play is because she’s a girl.”

Contacted this week, Chaput deferred questions about the Faheys to school administrators.

By most accounts, Mason’s play warranted her staying in the lineup. She may not have the extra-base power her brother does, but she has a keen eye at the plate and is adept at drawing walks. Late last season, she worked a bases-loaded walk on a close pitch in extra innings to force home the winning run in a huge victory over Hazen, the division’s first-place team.

Defensively, Boone praised his sister’s pitch-framing abilities, saying she presents pitches better to the home plate umpire compared with other catchers he has worked with.

“I’ve always been coached that baseball is mental toughness,” Mason said. “That’s one of my favorite parts of the game to break down. It’s such an intricate game like that, and there are so many ways to break it down. I love having baseball conversations, because I might pick up on something and Boone might pick up on something else.”

Mason has played on girls teams at Thetford in soccer and basketball, but baseball was always her true passion. She never gave softball real consideration. She made the Panthers’ varsity team as a freshman, becoming the first girl Chaput had coached in his decade-plus at Thetford and the only girl on an Upper Valley high school baseball team.

After not seeing much playing time her freshman year, Mason’s frustration began to mount last season, when she still wasn’t getting on the field as much as she hoped. When she asked Chaput what she could do to play more, Mason said Chaput did not provide a baseball-specific reason for keeping her out, instead telling her she needed to “be more confident and assertive.”

She approached dean of students Siobhan Lopez, who was acting athletic director. According to Mason, Lopez suggested she set up a meeting with Chaput and the coaching staff but would not allow her to have a parent come along.

“I’m not exactly comfortable having this type of conversation alone with my coaches. I would prefer to have someone on my side there,” Mason said. “(Lopez) was worried that would put the coaches in an uncomfortable situation. When she said that, I was really frustrated. How are you going to tell me, as a 16-year-old girl, I’m not allowed to have a parent there when I have a conversation with these coaches? You’re valuing the comfort of two grown men over one of your student-athletes. That was hard for me to deal with.”

Mason — who said her male teammates have never appeared to have an issue with her — played primarily right field after her conversation with Lopez but was on the bench during the playoffs as the Panthers advanced to the semifinals before losing in a rematch with Hazen. Following the graduation of starting backstop Ryan Malloy, though, Mason earned the nod behind the plate going into this season.

But in Thetford’s third game of the year, a key road win over White River Valley, junior first baseman Justin Robinson exited with an injury, and Mason, who had played some first base last year, took his place there. Meanwhile, the Panthers called up freshman Andrew Spooner from the junior varsity team to fill the vacancy at catcher — after Mason had helped Spooner with his defense in the gym at the beginning of the year.

“I try to be transparent with all the players about where they’re at and where they’re going to play and potential places where they might play,” Chaput said before Mason and Boone left the team.

While starting at first, Mason had her moments offensively, most notably a three-RBI double in a win at Harwood on May 6. Against Montpelier on May 16, her sharp ground ball in the seventh inning was too hot for the second baseman to handle, allowing the winning run to score in a 2-1 Thetford victory.

Spooner has a stronger throwing arm than Mason, but Boone said he much preferred his sister behind the plate due to her superior framing abilities. Still, when Robinson took back his spot at first base for the regular-season finale against U-32 on May 24, Spooner remained behind the plate and Mason was relegated to the bench.

“The biggest thing for Mason was not understanding why she wasn’t playing, even after asking repeatedly,” Boone said. “They couldn’t give her an example, they couldn’t give her a reason. It was very vague.”

The U-32 game ended up being suspended in the second inning due to rain, and Chaput said he was hoping to get Mason some playing time at first as Robinson continues to work his way back to full health. But at practice on May 25, he met with Mason and Boone to discuss the former’s role going forward, telling them Robinson would be at first base with Spooner catching and Mason occasionally filling in for Robinson.

Mason and Boone made their decisions that evening — Boone said he left the team not only for Mason, but also for other players who didn’t agree with the way Chaput was managing, specifically pointing out his lack of communication behind lineup decisions.

Bri Barnes, who took over as athletic director last summer, said “it was a shock” to her when the Faheys handed her their jerseys.

“As a female athletic director, I am deeply committed to gender inclusivity in TA’s athletics programs and in our community,” Barnes said in a statement emailed to the Valley News. “Though I’m new to TA, I take a lot of pride in the relationships I have built among our students, coaches, colleagues and families. While we continue to process information, communicate with coaches and assess our season, it is my goal to continue to foster a positive, equitable and supportive environment for all of our teams and players.”

Neither sibling will be at Thetford in the fall. Mason will take early college classes at Northern Vermont University-Lyndon, and Boone will transfer to Phillips Academy, a prep school in Andover, Mass. Mason has the option to play sports at Lyndon or at Thetford and said she has yet to make that decision.

That made leaving the baseball team an easier call for both of them, but it was a decision they struggled with for a long time. Mason said it is now hard to separate wanting her former teammates to do well and win with having a hard time watching Chaput succeed.

“I really hated the idea of quitting. I’ve never quit a team in my life,” Mason said. “To think that baseball was going to be the first team I quit, it seems ridiculous and heartbreaking because baseball is our favorite. It wasn’t an easy decision, (but) I don’t honestly question it. I’ve talked to the coaches, I’ve talked to the school, I’ve exhausted all the resources they’ve provided me and gotten nothing.”

Benjamin Rosenberg can be reached at brosenberg@vnews.com or 603-727-3302.