Triston Casas has flashed his personality from the moment he was called up to the big leagues. From painted nails to sun-tanning sessions on the grass, fans didn’t know what to expect from the rookie.

During his first full season, he made it clear. After starting slow in his offensive production and logging a lot of strikeouts, Casas lowered his hands in the batter’s box. He finished with the fourth-highest OPS of any player after the All-Star break.

Casas’ swift turnaround places him in a unique position. He’s young, he has little big-league experience, but he’s proven he knows what it takes to play at the major league level. He accepts criticism and changes to his routine to come out better after all the work. And Casas is using his position to guide the Red Sox’s next wave of prospects through their Fenway transition and beyond.

Manager Alex Cora has referred to Casas as the “MVP” of the Sox’s offseason for all the work he’s put in and the help he’s provided to others.

The 24-year-old attended Trevor Story’s infield camp earlier in January, where worked with Vaughn Grissom and prospects David Hamilton and Nick Yorke together on fielding and hitting drills, along with friendly games of knockout and pickup football.

Casas shines by encouraging the people around him. He posted Grissom taking swings on his Instagram story to show give Sox fans a glimpse of what he will bring to the team and to prop up the newcomer.

Triston Casas is taking on a leadership role among young Red Sox players

Casas continued his support for younger, newer players by attending the Sox’s rookie development camp. The prospects were happy to see him and to listen to his major-league wisdom.

“I’ve talked to him quite a bit. He reached out a little bit at the end of the year. He’s been great, and he’s been super helpful,” Sox prospect Roman Anthony told NESN. “He got here (Wednesday) so just picking his brain and seeing how his first full year went.”

Casas enjoys talking to prospects as much as they enjoy speaking with him — he’s especially confident in Anthony, whom he played against in high school and knew before they joined the Red Sox organization. Casas has given a vote of confidence to Anthony’s approach at the plate, specifically his walk rate, which has been sky-high in the minor leagues at 17.5%.

But besides getting to know each other as players, Casas is all for giving support off the field to the person behind the uniform.

“We’ve been getting to know each other more on a personal level more than baseball stuff,” Casas said. “I feel like that’s the best approach to take when meeting new teammates. Try to level with them. Try to understand their sense of humor and level of emotional intelligence.”

Boston fans have shown love for Casas the person and Casas the player, and the team is doing a lot of marketing surrounding him and young pitcher Brayan Bello. With any luck, extensions are coming down the pipe for both of them and Red Sox Nation will reap the rewards of Casas’ leadership for years to come.