The jersey belonged to Nick Adenhart, who has been in the Angels' hearts and minds since his death, at age 22, along with companions Courtney Stewart and Henry Pearson in a hit-and-run car crash in the early hours of April 9 in Fullerton, Calif.
Jon Wilhite, making a remarkable recovery from multiple injuries, was the lone survivor of the tragedy caused by a drunk driver.
Jepsen sat at his locker in Fenway Park on Thursday night. Off his left shoulder was fellow reliever Rich Thompson. The locker to Jepsen's right contained one item: The uniform jersey he would take into the dugout before the game.
"It's an honor to be able to do it," Jepsen said. "Nick was a close friend. We were together in the Minor Leagues, and we hung out in the off-season.
"Shieldsy was bringing the jersey into the dugout at the beginning of the season. When he had knee surgery, he asked me. `I'm not going to be here,' he said. `Will you take the jersey out?'
"It's awesome to take the jersey out, so he's out there with us all the time. I'll hang it in the dugout, then it's business."
Knowing Adenhart as well as he did, Jepsen feels it's the right thing to do. Kevin also believes Nick's presence can be an inspiration, and that it has brought this team together in a positive way.
"When you have things that happen to a team throughout the course of a season, there's only two ways to go," Jepsen said. "It will bring a team closer together, or everybody will go in their own direction.
"I feel this tragedy ... it's tough. But I feel it's one of those things we went through together, as a team, and we're all stronger for it.
"To lose one of your own, especially during the season, it's so tough. One night he's pitching, and the next day he's gone. Even guys who weren't that close to him still felt it and took it really hard. But I really think it made us stronger, and I think Nick would have wanted it that way.
"He was an extremely competitive guy who loved the game. He'd have wanted us to keep playing, and that's what we've done."
Thompson grew close to Adenhart during Spring Training when they lockered next to each other at Tempe Diablo Stadium.
"I got to know him a lot better, and really got to appreciate his sense of humor," Thompson said. "He'd have his earphones on, blasting his music, big smile on his face. He just had that talent to make you laugh. He'd been in big league camp since he was 19, so everyone knew the kid and really liked him.
"He'd grown so much over the previous six months or so. You could really notice it in the way he went about things. He was just getting started on that path. He was an outgoing guy who liked to have fun, but he was really serious about the game. He knew what he wanted to do and was determined to have a great Major League career.
"It's so sad to lose a guy who could do things so easily, who had so much in front of him. I know a lot of guys were hurt -- and still hurt."
Thompson watches his bullpen mate, Jepsen, carry the jersey into the dugout every night as part of the pregame ritual.
"When Jep takes the jersey out," Thompson said, "it's like Nick's still with us."