Director of Cricket Mick Newell snapped up the giant opener from Essex on a three-year contract in 2007.
Standing 6ft 10ins tall, Jefferson presents a real problem for bowlers as good-length deliveries turn into half-volleys - as supporters may remember from a few of his previous visits to Trent Bridge, where he scored three hundreds in 2004 in the C&G Trophy and the Championship.
His last season with Essex was blighted by a freak injury to his wrist after he accidentally pushed his hand through a bathroom window and damaged tendons. He returned to full fitness in time for the 2007 pre-season only to pull a hamstring, an injury which would trouble him throughout the summer.
He eventually made his debut in June against Lancashire in the Friends Provident Trophy, scoring an unbeaten 60, and also showed some glimpses of his ability in the Twenty20 Cup and NatWest Pro40.
Jefferson struggled to find form in 2008, recording an LV County Championship average of 18.10, but retains the confidence of Newell who believes his best is yet to come.
An intelligent, confident cricketer, Jefferson studied at Durham University and was part of the first wave of players on the UCCE system in 2001.
He left Nottinghamshire at the end of the 2009 season before joining Leicestershire. Unfortunately he has had to retire due to being diagnosed with a rare hip condition.