Born in Cardiff, Maynard attended Pentyrch Primary School, Radyr Comprehensive School, and then moved to Millfield School[REF] before attending Whitchurch High School for sixth form [REF]. Maynard made his way up the ranks with Glamorgan, starting in the county's Under-17s side at the age of 15.
After his debut, Maynard's seasonal first-class batting average increased from 11.66 to 22.60, with an overall average of 15.33 and a top score of 51 not out.