He was educated at Beths Grammar School in Bexley before studying Geography and Sports Management at Loughborough University.

[1][2] He played cricket for both Kent and the Loughborough MCC University team whilst a student.

[1] Riley made his first-class cricket debut for Kent against Northamptonshire in the 2011 County Championship.

He took his maiden first-class five wicket haul against Loughborough MCCU, taking figures of 5/76 during the season.

The England coaching setup had intervened to change his delivery during a training camp in 2015 and, despite a number of attempts to revert to his previous, effective action, which was described as having been "very fluid" with "the ability to bowl spin with good pace, control, guile, dip", he had been unable to recover his form.