Dermody, who was brought up from Triple-A Worcester to make his first major league start Thursday night against the Guardians, made the social media post in 2021. It has since been deleted, but captured screenshots continue to circulate.
The Red Sox said they were unaware of Dermody's tweet when the 32-year-old signed with the club in January. Once they learned of it, team officials met with Dermody, who went through mandatory anti-discrimination and harassment training in March.
"What Matt posted in 2021 was hurtful -- and we addressed this with him when we learned about it after he joined the Red Sox in 2023," team president and CEO Sam Kennedy said in a statement. "We cannot dictate the religious beliefs or political views of our players and employees, but we do require they treat people in our organization and ballpark with respect and professionalism."
Red Sox manager Alex Cora echoed Kennedy's stance.
"Obviously, as an organization we made this decision and done a lot of stuff to educate our players on the subject," Cora said sitting in the dugout at Progressive Field before the series finale. "I don't know how many organizations do it with their employees and their players as far as educating them about being inclusive, and obviously accepting everyone in your clubhouse and your working environment."
Dermody gave up two of Jose Ramirez's three home runs and took the loss as the Red Sox were thumped 10-3 by the Guardians.
Afterward, Dermody expressed some remorse for his actions.
"I do regret the tweet in the sense that it came out hurtful and it hurt a lot of people," he said. "That's the last thing I want to do is hurt people. A lot of people think that I'm against a certain group of people or whatnot. But I'm for everybody making it to heaven."
Dermody is expected to be designated for assignment Friday as one of several roster moves by the Red Sox.
Cora said it's not his place to have an opinion on Dermody's beliefs.
"Obviously, not too many people agree with the tweet of Matt's," Cora said. "I'm not here to tell him what to say or to do. But one thing for sure, when you put this uniform on, what we want is for people to be inclusive.
"I think the clubhouse is a reflection of the world. We've got people from different race, different beliefs, not just religious beliefs but also politics."
Information from The Associated Press was used in this report.