A big-hitting all-rounder, Henderson built himself a reputation in South Africa with Border and Warriors as a match-winner.
He made his first-class debut for Border in 1998/99 and has agreed a contract to play for Highveld Lions next summer.
Henderson was the Standard Bank Pro20 cricketer of the year in 2004/05 thanks to his ability with both bat and ball, a talent that has earned him South Africa A representative honours.
That prompted Kent to bring him to Canterbury as a replacement for fellow countryman Justin Kemp mid-way through the 2006 season. He also made his international debut in Twenty20 match against India at Johannesburg in December that year.
He returned to England with Middlesex and played a crucial role in the 2008 Twenty20 Cup victory at the Rose Bowl which earned them a place in the Stanford Super Series and the Champions League.
Henderson smashed 59 from 21 balls to see his side past Durham in the semi-final and added a crucial 43 from 33 deliveries against his former county in the final.
He signed a one-year contract extension towards the end of the season to keep him at the club for the 2009 campaign.
He played for the Crusaders in the inaugural Stanford Super Series.
In 2009 he again did well in the Twenty20 Cup, taking nine wickets and averaging over 20.