He is a Fullback, also playing on the Wing. Chisholm started playing rugby at Haywards Heath Reconstruction Finance Corporation, his talent earning him a place in Harlequins Elite Player Development Group and then promotion to the senior Academy. He was selected to play in two senior pre-season matches in 2009 before making his first team debut later that year against Newcastle Falcons in the LV Cup.
He continued developing and in January 2011 signed his first senior contract.
The 2011/12 season saw Chisholm make his first Premiership start in the opener against London Irish, playing on the wing. The constant presence of Mike Brown at Fullback and stiff competition on the wings limited Chisholm"s first team game time, but he did make 11 senior appearances (including 4 Premiership starts) in the season, scoring 5 tries.
His last try was scored in the dying moments of an away loss against Gloucester (his second that match), it secured Quins a losing bonus point and Chisholm a nomination for RPA "Try of the Year". His development has severely hampered by serious injuries which have limited his chances to play for the 1st XV.