A right-hand batsman and occasional seam bowler, Michael Thornely began his career with Sussex, where he spent three years before being released at the end of the 2010 season. Playing for Unicorns in 2011, he made an unbeaten century against Somerset and 97 against Nottinghamshire in the CB40 competition, yet suffered the frustration of playing Second XI cricket for four counties -- Somerset, Nottinghamshire, Essex and Kent -- without securing a contract.

Offered a trial by Leicestershire at the beginning of the 2012 season, his fortunes improved. After making 56 and 103 against Warwickshire in a Second XI Championship fixture, he was given his first-team debut in the Championship match against Glamorgan in Cardiff a week later and rose impressively to the occasion, falling only three short of a century in the first innings and making 131 in the second innings to secure a draw, batting for almost 12 hours over the two innings. He made a second first-class hundred against Essex later in the season and was rewarded with a contract for the 2013 and 2014 seasons.