It is thought, through historical records and the detective work of Sunderland based sport and social historian Keith Gregson, that Marshall sustained a severe knee injury which curtailed his rugby career.
He was educated at several schools, including Barnard Castle and Norfolk County, before gaining entry into Caius College, Cambridge in 1888.
Marshall first entered medicine when he joined the medical college, St. Bartholomew's, becoming a House Surgeon and the Clinical Assistant in the Throat Department.
On the outbreak of World War I, Bingham Hall in Cirencester was turned into a Red Cross Hospital and Marshall was made medical officer in charge of it.
In 1893 Marshall played his one and only England international tour when he was selected to face Wales as part of the Home Nations Championship.