Anybody that can handle Java should be able to handle PHP. I went from knowing nothing to being able to do an entire simple project in one week, but I already had experience with web scripting. It would take a bit longer if they don't have some experience with designing for web sites and scripting.
The only hard things in PHP are the subtle issues of security, error handling and performance, particularly if the site is open to the public on the internet. But those issues are hard and subtle is every language.