"I was turning 40 in 2007 and my wife said, 'Go and do this, it will be once in a lifetime,'" Vosseller said last week during the team's 12th annual Fantasy Camp at Salt River Fields.
That once-in-a-lifetime experience has turned into a yearly event for Vosseller, who like a lot of campers discovered that what initially caused them to come to the camp -- getting a chance to rub elbows with former Major Leaguers -- became less important than the relationships they made once they were there.
"It was something that I thought would be a very enjoyable experience," Vosseller said. "But I didn't realize the friendships I would get out of it. I began to realize that those relationships were what kept me coming back to camp. It became my fellow campers first, playing baseball second and then the former players wound up being third."
Vosseller's story is typical of many of the campers, who have bonded through their shared charity initiative of the "Camper Fund," which helps raise money for the D-backs' Outreach and Development program. The goal was to help kids in need attend the various D-backs Baseball Academy camps that are held throughout the year.
Over the years, they've formed teams to play Men's Senior League Baseball and been there for those who have suffered personal misfortune.
When this year's camp started with a mixer at Talking Stick Resort, one of the employees remarked that it was like a family reunion was taking place.
"I never thought I would quadruple the number of friends I had in Arizona just by coming to this camp a week every single year," Vosseller said. "There are at least 20-25 people here that I keep in contact with throughout the year and look forward to seeing each time."
It's likely that Vosseller's travel time to camp will be less arduous next year, as he is set to retire this summer after 27 years with the Air Force.
Of the nine times he's attended Fantasy Camp, Vosseller has traveled to Arizona from bases in Germany, England, Italy and Hawaii.
The toughest of all for him, though, were the camps he missed in 2011 and '12. The first was due to a six-month deployment in Afghanistan; the second was also for an Air Force obligation.
When he returned in 2013, he received the "Makes a Difference Award" that is awarded to one camper each year for positively influencing the experience of others. It is voted on by all the participants.
"That was really tough on me," Vosseller said of the two-year absence. "And to receive the 'Makes a Difference Award' when I came back was such an honor and so humbling to know that I was missed and was such an integral part of the camp. I'm really proud of being a part of this Fantasy Camp."