Have VWP; just need Visitor Extension?

[JaimieB]

I work for an athletic training facility and we currently have an athlete from the UK who is training at our San Diego facility; he is currently here on an VWP through the ESTA. We believe his 90 days is up in about 51 days and we would like to try to extend his visit, legally, so that he can continue training at our facility before the next competition begins.

We just need to file a Visitor Visa Extension, right?

[immihelp]

Stay can't be extended on VWP.