Arlyn "Arlie" Marshall began his lacrosse career at Southern High School in Baltimore where he was selected All-State in 1952. At Johns Hopkins University, Marshall was selected as the outstanding freshman athlete in 1953 and the outstanding senior lacrosse player in 1956. He was honored as an honorable mention All-American in 1955 and a first-team All-American midfielder in 1956. Marshall was the team captain for the Blue Jays in '56 and represented Hopkins in the 1956 North-South All-Star Game.
Marshall played club lacrosse for the Mt. Washington, Maryland, Baltimore, and Carling lacrosse clubs from 1956-68. In 1969 he obtained his first head coaching position for the Carling Lacrosse Club. He also served as head coach for the Pyle/Chesapeake Lacrosse Club and the Severna Park Lacrosse Club. In 1977, he became the head coach of the Maryland Lacrosse Club. His teams won the U.S. Club Lacrosse Association championship six times. Marshall was selected as the USLCA Coach of the Year in 1982 and '87.
Marshall was the head coach for the U.S. alternate teams selected for the 1982 and 1986 World Championships. His coaching career climaxed in 1990 when he was named the head coach of the U.S. National Team, which successfully defended its world title at the 1990 ILF Championship in Australia.