Tuesday, more than three years after he was told he had a year to live, Youmans put on a D-backs uniform, played on the Spring Training fields of his favorite team and had lunch with team owner Ken Kendrick.
"It's overwhelming in a good way and I'm humbled by it," Youmans said. "I feel blessed to be here in more ways than one."
When given his stage-four diagnosis of pseudomyxoma peritonei, Youmans refused to just give up. From his hospital room in Scottsdale he searched for a doctor that would help and found Dr. Andrew Lowy at the UC San Diego Moores Cancer Center.
Willing to do whatever it took to survive, Youmans quit the job he had held for 12 years and his friends packed a few bags for him and he went straight from the hospital to the airport. He had no money and no insurance, but Youmans was not to be deterred.
"Since Day 1 of my diagnosis and being told I had a year to live I didn't take that as reality," Youmans said. "I said, 'That's not going to happen, that's not me.' I'm going to find out a different reality and a different future for myself and I've been fighting for that ever since. It's about a positive mental attitude. That and the support of family and friends and my doctors is why I'm here."
Youmans has had two cytoreductive surgeries, which doctors have nicknamed "The Mother of All Surgeries," and he's been through two years of chemotherapy.
While it has robbed him of some of his weight and physical strength, his determination has never wavered.
"Although I live for the moment, I can't wait for the next day and what it could bring," Youmans said. "Physically, I've definitely felt like I'm out of gas, but mentally I've always had that motivation to just keep going."
In October of 2011, he participated in a triathlon with his friends.
"We all celebrated life that day," Youmans said. "It's something I never thought I'd be able to do even before cancer. I didn't finish first by any stretch of the imagination and I didn't want to, because it was about enjoying the day and enjoying the moment."
Following his second surgery last January, his friends told Youmans they would send him to D-backs Fantasy Camp -- a bucket list item for someone who had been a diehard fan -- if he was healthy enough.
"I said absolutely," Youmans said. "And here I am. We did it. I'm going to do the same thing next year. This fantasy camp helped motivate me to fight cancer as hard as I possibly could. It wasn't the sole factor, but it was part of it and it's going to be a bigger part of it next year because I know what it's all about now."
Youmans story, which he shares on his website pmpwarrior.org, has touched camp participants and the former D-backs players as well.
"Incredible, isn't it?" D-backs third base coach Matt Williams said.
"That he's out here kind of makes you realize that maybe things in your own life ain't so bad after all," former D-backs first baseman Mark Grace said. "What an incredible story."
It's a tale that Youmans still believes will have a happy ending and one he hopes will inspire others facing similar challenges.
"I'm fighting something that's trying to kill me and I'm not going to let it," Youmans said. "I'm going to do everything I can. If it does get me someday, you can look back and say, 'He fought as hard as he possibly could and unfortunately it got him.'
"I'm not the only person that has to deal with this, I'm not the only person who's had to deal with it, or will deal with it in the future. If I can somehow set a standard for other people, or be an example, or be a motivation for other people to look and say, 'If he did it, I can do it,' that's what I want to do. Every day that goes by, it's in the record book. Every single day is a notch, it's a base hit and that's the way I look at it."
Starting in February, Youmans will once again begin chemotherapy treatment. This time he will do so with a whole bunch more people behind him.
"Remember," Kendrick told him Tuesday, "we'll be here for you."