Professionals looking to reacquire an amateur status will need to wait 30 days from their last match.
Last match - Any player who makes a teamsheet regardless of taking the field or not will still be viewed as having "played"
National Registration Regulations (NRRs)
(a) A Player registered as a Professional cannot re-register as an Amateur until at least 30 days after his or her last Match as a Professional. Where the National Leagues administered by FA have different Season timings to Member Federation Competitions, Competition Rules may provide an exception to allow a Professional in a National League to return to a Member Federation Competition as an Amateur with a shorter stand-down period.