New England Revolution defender Stephen McCarthy changed his number from 26 to 15 ahead of the 2013 MLS season in honor of late Crew midfielder Kirk Urso, who passed away due to a congenital heart defect on August 5, 2012. McCarthy and Urso were teammates for two seasons at the University of North Carolina, helping the Tar Heels to an appearance in the 2010 College Cup after McCarthy missed 2009 due to injury.

McCarthy transferred to UNC from Santa Clara in January 2009 and just as he did when Ben Speas landed at North Carolina in 2011, Urso was the first Tar Heel to make an impression on McCarthy.

"I transferred in and my first memory of [Urso] really stuck. I was a transfer coming in and it was my first day of training -- it wasn't even a real training it was just kind of a kick-around in the gym -- there were no coaches there and we just played small-sided games," McCarthy recalled. "Kirk was just so serious. Every ball, he was going so hard and going after tackles. In my head I was thinking 'This guy is crazy.' I didn't think I liked him very much when I first met him."

He continued, "As my playing went on with him and I got to see who he was off the field as well as on the field, I started to realize how good of a human being he was. He was the most serious player I think I've ever played with because he wanted to win so badly on the field. And then when you got off the field he was just the nicest guy. He was the smartest, the best student on our team. I had some classes with him, he helped me in school as well as on the field. When I transferred, he was always happy to be around and hang out and talk. We kept in touch when I went to New England and he went to Columbus as well. It's tough."

In sports, a player is almost as identifiable by his or her number as they are by name. After all, McCarthy incorporated his number into his Twitter handle: @BigMacca26.

Heading into his third season in MLS, McCarthy will no longer don the number 26, but instead play in his dear friend's memory with the number 15 on his back.

"I was just thinking of Kirk, and I just thought [changing to number 15] would be something nice to do for him and his family as well as for me because I want to keep him in my mind all the time," he explained.

"It's going to be important to me because I'm not just playing for me, but for him as well," he continued. "I want to be playing even harder for that reason."

Number 15 to honor my friend Kirk Urso. He will have my back all season — Stephen McCarthy (@BigMacca26) January 7, 2013

The Kirk Urso Memorial Fund was established by the Crew Soccer Foundation in late 2012 to provide a platform to develop and support youth heart health research and programming to honor Urso's memory. The Fund is in partnership with the Children’s Heart Foundation, which is dedicated to bringing health, hope and happiness to children impacted by congenital heart defects by funding the most promising research to advance diagnosis, treatment and prevention.