NFL Commissioner Roger Goodell talks with youth football players. (Tom E. Puskar/ AP Images for NFL Network)
Pop Warner football, which is the United States' largest football program for young people, saw an almost 10 percent drop in participation, reports ESPN.com's Steve Fainaru and Mark Fainaru-Wada.
According to the report, Pop Warner football, which began in 1929, lost 23,612 players in 2012, a 9.5 percent drop from 2010. That is thought to be the largest two-year decline since the organization began keeping statistics.
Pop Warner officials say there are several factors in the decline, including the trend of athletes focusing on one sport. One doctor believes it is the concerns about head injuries that is the number one cause in the decline.
"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," said Dr. Julian Bailes, a former Pittsburgh Steelers neurosurgeon whose 10-year-old son, Clint, plays Pop Warner outside Chicago. "We need to get it right."
More from ESPN.com:
The statistics, which have not been previously disclosed, are consistent with declining participation rates reported in youth football across the country. 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. The downward trends in youth football participation coincide with a series of ominous reports about football and brain damage in the NFL. In 2005, the first of dozens of confirmed cases of former NFL players with neurodegenerative disease was reported.