Gainey played halfback for coach Dillard Adair and rushed for 1,406 yards as a senior scoring 20 TDs and averaging 9.5 yards per carry. Gainey was known for his great speed. He scored on runs of 94, 90, 78, 68, 64, 62 and 61 yards his senior year. In 1954 Colorado City beat Seymour 41-27 in the bi-district playoffs with Gainey accounting for 269 yards and 4 TDs. Colorado City lost to eventual state champion Phillips 34-21 in the regional championship game. His #31 jersey was the first to be retired in school history. An accomplished track star, Gainey was the 1A state champion in the 100 and 220-yard dashes in 1954 and 1955. At the 1954 meet he was the high point man with 20 ¼ points and in 1955 he set a state record with a time of 20.9 in the 220-yard dash. Gainey received a track scholarship to the University of Texas and was a member of two world record relay teams.