The Salamanca, N.Y.,-native played his collegiate football at Colgate, preceding Mark van Eeghen both at Colgate and with the Raiders. The Raiders selected Hubbard in the 11th round of the 1968 draft. He played for the Raiders from 1969-75 and finished his career with one year with the Detroit Lions in 1977. His best season came in 1972 when he rushed for 1,100 yards on 219 carries with 4 TDs. Hubbard ranks as the 5th leading rusher in Raiders history with 913 carries for 4,394 yards and 22 TDs.
He played alongside numerous Hall of Famers in some of the most important games in the early history of the franchise.