Pop Warner, the nation's largest youth football program, saw participation drop 9.5 percent between 2010 and 2012, according to data provided to ESPN's “Outside the Lines.” Many are citing concussion concerns as the primary reason for the dropoff.

Pop Warner officials do not attribute the decline to the dangers of head injuries, but the organization's chief medical officer, Dr. Julian Bailes, believes that is the main reason.

“Unless we deal with these truths, we're not going to get past the dropping popularity of the sport and people dropping out of the sport,” Bailes, a former Pittsburgh Steelers neurosurgeon, told ESPN.com. 'We need to get it right.”

According to the same “Outside the Lines” report, USA Football, a national governing body partially funded by the NFL, said participation among players ages 6 to 14 fell from 3 million to 2.8 million in 2011, a 6.7 percent decline.

Pop Warner and USA Football attribute their decline to the economy and young athletes specializing in a single sport, ESPN.com reported. The ESPN.com report is here.