NEW YORK -- John Sterns chooses to remember the fireworks from his 22nd birthday. Given the circumstances, positivity is his new weapon.

While the Marine spent the day on a foot patrol in Afghanistan in September 2010, his life as he knew it vanished. Just under four years into his tenure with the military, an Improvised Explosive Device (IED) exploded next to him, removing his leg from the knee-down.

Almost two years later, Sterns walked into Citi Field on Friday with a below-the-knee prosthetic as a member of the Achilles Freedom Team for Wounded Veterans. The organization urges paraplegic veterans to set athletic goals and provides them with resources, such as travel expenses, race fees and hospitality accommodations. The Mets hosted 40 wounded Achilles soldiers and their families for Friday's Subway Series opener.

"It means so much to the team to come and enjoy themselves at a baseball game," Achilles Freedom Team for Wounded Veterans director, Genna Griffith said. "It helps them forget about the challenges that they're facing. There's nothing more American than going to a baseball game. It's just more meaningful to this population than one could imagine."

Before the accident, the farthest Sterns had ever run was 16 miles. Sterns completed a half marathon, 13.2 miles, at Walt Disney World in Orlando, Fla., in 2 hours and 21 minutes on Jan. 5. On Sunday, he'll be running in the 10th annual Achilles Hope and Possibility five-mile run in Central Park, along with the 39 other soldiers, marines and Navy Corpsmen and their families.

But Sterns will take it easy on Sunday. He has other plans. On Wednesday, he's competing in a 100-meter qualifier in Oregon, where the top two finishers will be sent to the 2012 London Paralympic Games.

The turn-around wasn't easy, and it couldn't have been completed without help. When Sterns returned to the United States in September 2010, he was unsure when or whether he would ever walk again. Now the man who dreamed of becoming a superhero at age 4 is finding ways to convince us all that might be possible. He attributes his positive outlook to the goals he set with Achilles, and Sterns hopes to participate in a marathon with them sometime in the near future.

"They've set new goals for me," said Sterns, a native of Pompeii, Fla. "They actually paid for my whole trip out here. Everything is paid for -- rooming, food, flight. Any race I do, they take care of everything like that."

Achilles was founded in 1983, but the Freedom Team was founded in 2004. With help from the Walter Reed Army Medical Hospital in Washington D.C., the organization has sponsored over 1,000 veterans to do marathons as part of their rehabilitation process.

"It helps them get back into a normal life where they can be active, they can go back to school and back to work," Griffith said. "It brings back the idea of setting goals and achieving them. We are happy and honored to serve so many who have made incredible sacrifices for our country."

Leeann Tweeden, former correspondent for "Best Damn Sports Show Period" and current host of "Poker After Dark" on NBC, joined the organization as an ambassador when she heard about the opportunity to help wounded veterans. She handed out medals to paraplegic finishers at the Los Angeles marathon, and jumped at the chance to help in Sunday's race, as her husband who serves in the Air Force is from New York.

"Through two wars, a lot of these guys and girls have been injured and they've lost a lot of limbs," Tweeden said. "Guys come home, they get depressed, then they get angry and then they go, 'OK, what can I do with my life?' It gives them hope, it gives them a goal, it gives them something to do with their life so they can kind of focus on something else other than being injured."

Achilles has also visited the Red Sox, the Yankees and the Padres in past years.