On Sunday, more than 50 Vikings will represent causes close to their heart with custom-designed kicks.

Among players participating in the NFL's annual My Cause My Cleats campaign, some are representing their personal foundations; some are raising awareness about an illness or condition that hits close to home, such as C.J. Ham, whose mother is battling pancreatic cancer; and some are focused on inspiring and advocating for young people.

Vikings.com writers Craig Peters and Eric Smith spoke with tackle Brian O'Neill, quarterback Sean Mannion and running back Ameer Abdullah about the personal connection or motivation behind the causes they chose.

Below are their stories.

Brian O'Neill — Autism Speaks | By Craig Peters

Brian O'Neill comes from a tight-knit family.

The 24-year-old is the youngest of four siblings and is honoring one of his sisters, Lorraine, 30, and Autism Speaks with his cleats.

Autism Speaks promotes solutions for the needs of individuals with autism and their families. The organization provides advocacy and support for people with autism and works to increase understanding and acceptance.

An estimated one-third of people with autism are nonverbal, including Lorraine, which prevents Brian from staying connected across the miles through phone calls.

"The only time I can [communicate] with her is when I'm at home, but I try to get back home as much as I can," he said. "It's a different relationship, but it's a unique one and a special one for sure."

Brian said Autism Speaks does "a lot of great things for a lot of people," and he appreciates the opportunity to increase awareness.

"I think the more that people do talk about autism and understand it, the better it is for the families who go through it because more people have an idea of what it's like," Brian said. "I hope that process of people learning and continuing to expand their knowledge continues."

Sean Mannion – Team Gleason | By Eric Smith

Sean Mannion will be wearing customized cleats for the first time in his NFL career. And he's picked a cause that is near and dear to him and his family.

The Vikings quarterback is honoring Team Gleason, an organization that supports those with Amyotrophic lateral sclerosis (ALS), a neuromuscular disease that causes neurons in muscles to die. Steve Gleason, a former player with the New Orleans Saints, was diagnosed with ALS in 2011.

"Anything I can do to bring attention to that and bring attention to what Steve is doing for people with ALS, it's the smallest gesture I can make," Mannion said. "I'm proud to be wearing these cleats."

Mannion's father-in-law, Mike Lopez, passed away in January of 2003 after being diagnosed with the disease in 1996. He was 49 years old.

Lopez was a defensive back at Oregon State from 1982 to 1985 and earned All-Pac-10 Conference honors as a senior in 1985 with six interceptions.

Mannion, who also played at Oregon State, later married Lopez's oldest daughter, Megan.

"I was only able to meet him once before he passed … me and Megan had just started dating," Mannion said. "But he was just a really, really great guy. A great man.

"Just a great father to Megan and her sister," he added. "It's unfortunate I wasn't able to get to know him better. But I just know from the way Megan talks about him that he was a tremendous father."

Team Gleason has raised more than $10 million for ALS research and support since 2011.

Ameer Abdullah – Black Youth Project | By Eric Smith

Pick a random Tuesday during the season, and it's likely that Ameer Abdullah is giving back to the Twin Cities community.

The Vikings running back has already spent time this season at the Hennepin County Juvenile Detention Center. He also spent an afternoon at the Southside Boys & Girls Club in Minneapolis and is on the Vikings Social Justice Committee.

Abdullah's cleats will support the Black Youth Project, which aims to empower young African American. According to the Black Youth Project's website, the group focuses on "attitudes, resources and culture of African American youth ages 15 to 25."

Abdullah said he hopes those impacted by the Black Youth Project will see his cleats and be inspired to "create and be more than what is expected of them."

"Just set a new standard for themselves every single day," Abdullah said. "I'm a guy who didn't come from much but has accomplished quite a bit in my young life.

"I feel like everyone has that opportunity, it's just how you apply yourself and apply your mind in certain circumstances," he added.