All AYSO volunteers, Passantino said, are subject to background checks and must complete the organization's "Safe Haven" training program.
No players or parents have reported abuse by Pimentel to AYSO, but the league is encouraging players' parents to contact authorities if they have any relevant information.
Neighbors on a quiet street off Irvine Avenue near the Costa Mesa city line said they were shocked to hear about Pimentel's arrest.
On a gray afternoon, as rain dripped from the toys and lawn decorations sitting outside stucco houses, some described Pimentel as friendly and outgoing.
One neighbor who declined to give his name said he's known the family for more than 20 years and is skeptical of the charges.
He said that Pimentel was a touchy-feely sort, but not creepy, and is a good father.
Erin Mosher, 33, was also surprised about the allegations, she said, as her 4-year-old son darted around her legs.
"I could see nothing like that from him," she said. "He's good with the kids. We've known him for years."
Pimentel, she recalled, seemed to be heavily involved with youth sports and would often joke around with her son about playing tee-ball when he got old enough.
She said she's not worried — "It is what it is."
"It's kind of unbelievable," she said. "But until there's evidence and stuff, you never know."
— Los Angeles Times Staff Writer Richard Winton contributed to this report.