LONDON (AP) -- When Jesse Ravelo first met Jamel Herring, the veteran boxing coach encouraged the young U.S. Marine sergeant still mourning his 2-month-old daughter's death to work out his grief in the ring.
Herring took Ravelo's advice all the way to the Olympics.
After two tours of duty in Iraq, Herring laughs at the idea he'll be nervous when he takes the London ring for his first bout Tuesday. The American light welterweight feels his military training and the tragedy of his daughter's death have prepared him for anything Kazakhstan's Daniyar Yeleussinov can throw at him.
"I've already been through the worst times," Herring said after a recent workout. "This right here, it's not an easy break, but it's a lot different from being in Iraq. I've been through the hardships. I know what it takes. I'm mentally strong. I know what I've got to do when I go out there."
The U.S. boxing team seemed in danger of falling apart earlier this year until three military men took on leading roles. Head coach Basheer Abdullah is a veteran officer who coached in the Army's training program for 15 years after his own amateur career, and Ravelo is from the All-Marines boxing program.
Herring has emerged as a team captain and the clear leader of the Americans, who have the largest team in London. The Long Island native leads the cheers from the stands during the Americans' fights, and he looks out for his younger teammates with constant humor, occasional advice and a nonstop barrage of cajoling tweets.
"He's a good leader, and he gets the guys on their toes," Ravelo said. "He's a very funny guy, always getting along with everybody. He's always joking around and playing around. It's nice to have a guy like him in a camp, keeping everybody loose."
Herring served in Iraq in 2005 and 2007 as a field electrician, losing friends and fellow soldiers while navigating Fallujah and avoiding roadside bombs. He came home in 2008 expecting to fight for the Marine boxing team at Camp Lejeune, but his plans were interrupted when his daughter, Ariyanah, died in her crib a year later.
Herring stayed away from the gym for several months. When he returned, he had a new perspective on his sport.
"It makes me just better overall as a whole person," Herring said. "I appreciate things more, especially in my own life. Not just with my military service, I've seen a lot of people come in and out of my life, especially with my daughter's situation. I just feel like I'm a lot tougher as a person, a better person."
Herring mourned the third anniversary of his daughter's death on the night of the opening ceremony.
Herring's boxing career picked up after Ravelo took over the Marine program in 2010, but thought again about quitting after a blowout loss at last year's national championships. Ravelo went back to work, determined to turn this soldier into a world-class boxer.
"He had the talent, but he just needed somebody to bring it out," Ravelo said. "He had a lot of personal issues that needed to be worked out. When I took over the team, we had a conversation and tried to fix his personal problems. I said until you fix those problems, your talent is not going to come out. I try to bring a family atmosphere into it between him and I."
After another pep talk from Ravelo, Herring won the U.S. Olympic trials. But he didn't qualify for London at the world championships in Azerbaijan, forcing him to make a trip to Rio de Janeiro this summer for his last chance.
Only three Americans qualified for the Olympics before that Rio event, one reason USA Boxing changed coaching staffs just a few months before the games. While USA Boxing worked on hiring Abdullah, Ravelo and the rest of the staff, Herring took over as a leader for the young American fighters, taking over as the team captain for the Rio tournament where six Americans earned Olympic qualification.
"I was more determined," he said. "I was more hungry. I just wanted to win it. Having these guys around really helps me, motivates me. They make me want to win it even more."
Ravelo made sure Herring kept his leadership role on the road to London. Each of his teammates cites Herring's ebullient personality and military work ethic as a reason the U.S. squad is off to a 4-1 Olympic start, winning its first four fights before light heavyweight Marcus Browne's narrow loss Monday.
Herring won't be in the ExCel ring for the first time Monday, either. He fought a test event at the arena several months ago, further whetting his appetite for an Olympic shot.
"I'm still building myself to be better every day," Herring said. "That's how I always think. Right now, I feel good about myself and what I accomplished. I came from the bottom up to the top."