The event, held annually since 1986, has raised over $4.87 million to help find a cure for cystic fibrosis, a fatal disease afflicting children and young adults.
Flessner, who was diagnosed with cystic fibrosis as a 2-month-old baby on May 1, 1989, was 5 years old when he started participating in the Mariners Care tournament. It's a can't-miss opportunity for the baseball fan; a chance to work hand-in-hand with his big league heroes to fight his illness.
"The man [the professional athlete] really matches the perception for so many of the guys that come out here. It makes a big impact to see them and see that they're role models. With cystic fibrosis it's a lot about compliance and doing your medicine," said Flessner, who spent 30 minutes that morning taking inhaled antibiotics.
"To see all the hard work they do, it's similar to the hard work I have to do keeping my treatments up and everything like that. It's cool."
Jonathan's father, Paul, took an early and active role in combating cystic fibrosis after his son's diagnosis. Working on both the research and fundraising side, Paul Flessner is well aware of the importance of the money raised by the golf tournament, as well as the post-tournament dinner featuring live and silent auctions that organizers expect to raise as much as $200,000.
Still, he says the most important thing the players can do isn't to raise money, it's to simply show up.
"The Mariners have a ton of positive role models, for them to come out here and share their day and get the kids excited about staying positive," Paul Flessner said. "A big part of any illness is to be positive and a chronic illness can wear you down. To see your idols, and play golf with them, [Jonathan] looks forward to this all year long."
First baseman Justin Smoak and outfielder Raul Ibanez hosted the tournament, soliciting their teammates to come out and support the cause. It's never much of a challenge for the hosts, as a number of teammates are always eager to sign up.
"I think we're all excited to finally get a day off here at home, and there's nothing better than spending it out here playing golf for a good cause," Smoak said. "I've been a part of it the past two or three years now and to be able to come out here and raise money for cystic fibrosis, and see how it affects the families and the kids, we're trying to help. So it's always definitely fun to get out here."
By doing so, Ibanez and Smoak join the ranks of former Seattle players like Jay Buhner, Randy Johnson and more who have helped organize the event.
We don't get many off days, especially in the Pacific Northwest," Ibanez said. "For the teammates and coaches to come out and support this event and all these great people, I think it's a beautiful thing and a beautiful cause."
"They always get some leaders in the clubhouse that go out to their teammates and say, 'this is why we're doing it,'" said Harley Franco, who is the CEO of Harley Marine Enterprises, the event's primary sponsor. "You've got to have some leaders. Every generation there's a new team leader that recognizes and identifies that this is very important."
Because of that leadership, as well as the support and dedication of families like the Flessner's, the tournament has had a great deal of success, raising nearly $5 million for the foundation since its inception in 1986. That money goes to researching medications and antibiotics to help those with cystic fibrosis deal with the symptoms, as well as searching for a cure.
"We have a continuing need to develop new treatments," Jonathan Flessner explained. "Treatments that did work once upon a time, the body becomes resistant to those. That's why the work that the foundation does is never over and it's important we continue progressing."
As a yardstick for success, however, all agreed that the amount of money the tournament has raised in those 28 years is secondary. Since the Mariners first partnered with the Cystic Fibrosis Foundation nearly 28 years ago, the life expectancy for someone struggling with the disease has nearly doubled, from approximately 18 years old, to nearly 40.