(CBS) Long before his memorable year-long retirement party that culminated in a World Series championship with the Cubs in 2016, the reputation on David Ross wasn’t that of a terrific teammate.

Back in 2008, Ross had a reputation that he wasn’t proud of. It’s something undocumented until a story he penned this week for The Players’ Tribune in which he discusses baseball’s best “Glue Guys” — the teammates you want to have.

Ross became that thanks to a harsh dose of reality handed out from Theo Epstein, then general manager of the Red Sox, after their team had been eliminated from the playoffs by Joe Maddon’s Tampa Rays in 2008.

Here’s how it happened, as Ross wrote:

“In 2008, after we had lost to the Rays in the ALCS, I was in the Red Sox clubhouse cleaning out my locker when Theo Epstein walked in and asked to speak with me. We ducked into Terry Francona’s office, which had already been cleaned out, for what amounted to an exit interview.

“It had been a crazy two months for me. I had been released for the first time, by the Reds, and at that point, I thought my career might be over. But then Boston picked me up, and, after a deep playoff run, I was about to be a free agent.

“Theo and I sat down, and he shot me straight: The Red Sox weren’t going to re-sign me. He said that he loved having me in Boston and that he’d be in touch, and he thanked me for everything I had done in my short time with the team.

“Then, he dropped a bombshell on me.

“He wanted me to know that I had a … reputation. I’m trying to remember his exact words, but basically, he said that I was known as a guy who didn’t understand or didn’t want to accept his role — a role that was basically that of a backup or role player.

“That I was selfish.

“A bad teammate.

“That hit me hard because that’s not the kind of player I thought I was or wanted to be. That’s not the kind of player anybody wants to be. That’s the worst kind of player.

“Theo reiterated that these weren’t things he had seen in me, only what he’d heard through the grapevine. And knowing that I was about to be a free agent, he wanted me to know. I appreciated his honesty.

“’Reputations die hard,’ he said.”

Ross played just eight games with nine plate appearances in Boston that 2008 season. He rejoined the Red Sox in 2013 and was part of their World Series championship won after Epstein’s departure to Chicago.

When the Cubs signed Jon Lester to be their ace in 2015, Epstein also signed Ross to be his personal catcher. Ross would emerge as a key clubhouse leader for a young team and cemented his place in Cubs history with a home run in Game 7 of the World Series, the final game of his career.

Ross recently penned a book entitled “Teammate,” which documents his life in the game of baseball.