But, if anyone still needs a second opinion, just ask another player in the Padres' clubhouse or San Diego manager Bruce Bochy or head athletic trainer Todd Hutcheson about her work. They'll say not only does she help the players in avoiding injuries, but her personality blends in easily on a big-league team.
In the last week, much has been made about Calabrese's presence in the dugout after former Mets player and current New York broadcaster Keith Hernandez said on the air that "women don't belong in the dugout." Hernandez later apologized for the remarks.
To Calabrese and the Padres, it isn't about being a man or a woman; it's about being the best person to do the job.
"Kelly's a part of this club, part of this training staff," Bochy said in reaction to Hernandez's comments. "She plays a major role with this club helping guys getting ready for the ballgame."
It all started with a little bit of luck.
"I've always had a passion for sports," said Calabrese, who played volleyball at Lake Erie College, about 30 miles east of Cleveland. "Baseball just kind of fell into my lap in massage school."
While at massage school in Cleveland in 1995, Calabrese was paired with a man who wanted a sports massage. Afterward, he referred Calabrese to some of his friends, who happened to play for the Indians at the time. When some of those Cleveland players got traded to Atlanta, Calabrese still worked on them on an individual basis, and that's when she met Klesko.
She was unsure about following Klesko from Cleveland out to San Diego, leaving behind the many clients she had built up. But she decided to make the journey on what she called "a leap of faith," one that has paid off.
After spending two years with the Padres on a part-time basis, the club was looking to hire someone full-time in 2003, a role perfectly suited for Calabrese.
"Having the team see the value in what I do was wonderful, and then I just got my foot in the door a little bit," she said about working part-time with the Padres. "And once our head trainer realized the value of having me around, it was an easy decision for him."
The title of "massage therapist" can be a little misleading concerning what Calabrese does. It's more than giving massages. She works on players' aches and pains, helping to avoid injury or further injury. Hutcheson said that since hiring Calabrese, who works on 10-15 players each day, there's been a decline in the everyday muscle pulls sustained during a big-league season.
Padres utility man Geoff Blum said Calabrese has helped him stay off the training table, and that she's had no problem handling herself in the dynamic of a Major League clubhouse.
"She does a good job of meshing with the guys," Blum said. "We all take a lot of verbal abuse in here and she's pretty willing to give it out and take it. I think she's a good addition to club.
"She's a rare breed. It's intimidating at times [in here], but I think she has the right personality to put up with professional baseball players. Thank God."
Calabrese said the issue of gender hasn't been an issue for her, save Hernandez's comments last week. She knows, however, that being the first woman hired full-time on a Major League training staff comes with responsibility, and she is glad to take it on.
"I think it's important that women have somebody connected with Major League Baseball, because they really don't," Calabrese said. "There are a lot of women fans out there, and a lot of young girls that are fans, and they don't have a woman that they can see visibly.
"There are a lot of women behind the scenes and in the front offices, but there's not a woman on the bench or on field that they can relate to. So, I'm happy to be that person."
As the only woman on staff, however, Calabrese does face one minor hardship.
"I joke around about it, but the toughest issue for me, being a woman and being the only woman, is the fact that I always have to wear men's clothes because that's all they order," she said. "Everything's so big on me, but other than that, it's really not an issue."
Calabrese may have some big clothes she can't fill, but that's the only thing about her that hasn't measured up.