Passage: Nixon was offered a tuition grant to attend Harvard University but Harold's continued illness and the need for their mother to care for him meant Richard was needed at the store. He remained in his hometown and attended Whittier College with his expenses covered by a bequest from his maternal grandfather. Nixon played for the basketball team; he also tried out for football but lacked the size to play. He remained on the team as a substitute and was noted for his enthusiasm. Instead of fraternities and sororities, Whittier had literary societies. Nixon was snubbed by the only one for men, the Franklins; many members of the Franklins were from prominent families, but Nixon was not. He responded by helping to found a new society, the Orthogonian Society. In addition to the society, schoolwork, and work at the store, Nixon found time for a large number of extracurricular activities, becoming a champion debater and gaining a reputation as a hard worker. In 1933, he became engaged to Ola Florence Welch, daughter of the Whittier police chief. The two broke up in 1935.After his graduation from Whittier in 1934, Nixon received a full scholarship to attend Duke University School of Law. The school was new and sought to attract top students by offering scholarships. It paid high salaries to its professors, many of whom had national or international reputations. The number of scholarships was greatly reduced for second- and third-year students, forcing recipients into intense competition. Nixon not only kept his scholarship but was elected president of the Duke Bar Association, inducted into the Order of the Coif, and graduated third in his class in June 1937.

Question: What was the biggest factor for Nixon to drop playing football?
lacked the size to play