Pedzisa mutsara unotevera: Marshall akatambira chikwata chenyika pakati pa 1982 na 1987, achikwikwidza paMitambo yeOlympic ya1984 muLos Angeles. Marshall akamiririrawo Australia paMakwikwi eNyika maviri; 1983 yakaitirwa muBrazil uye
1986 yakaitirwa muSoviet Union.