Sanderson is a product of the Colchester UnitedAcademy. He made 10 loan appearances for Chelmsford City in early 2011 before signing his first professional deal with the U's on 6 May 2011. He made his debut for the first-team as a late substitute for John-Joe O'Toole the following day in a 2–1 home victory over Bristol Rovers.[4][5]
Sanderson had to wait for almost three years for his second Colchester United appearances. He came on as an 84th-minute substitute for David Wright in a 2–1 away defeat to Leyton Orient on 1 March 2014.[6]
Ebbsfleet United
Following his release from Colchester, Sanderson joined Conference South side Ebbsfleet United during the summer of 2014, linking up with the club for their pre-season activities. His signing was completed on 5 August 2014.[7] He was sent out on loan to Lewes on 11 August,[8] making two appearances.[9] He then made his first and only league appearance for Ebbsfleet as an 84th-minute substitute for Charlie Sheringham on 4 October during a 3–0 away win over Farnborough.[10] He had already appeared in Ebbsfleet's 2–0 Kent Senior Cup defeat by Charlton Athletic and as a substitute in their 7–1 FA Cup win over Hythe Town.[9]