"I will not be coming back for the 2014 season," Martin said on his Instagram account. "I have decided to move on to the NFL and declare for the draft. Thank you Trojan Family for all that you've done for me! This will be a season I will never forget as long as I live and I wanna thank the coaches, my teammates and the fans for all that we've endured as a family! I am and always be a Trojan for life."
Martin was a first-team All-Pac-12 performer in 2013 in his first year playing center. He suffered a knee injury in the season finale against UCLA and did not play in the team's Royal Purple Las Vegas Bowl victory over Fresno State.
He was named a team captain in 2013 in addition to being the USC offensive lineman of the year.
Martin originally broke into the starting lineup as a true freshman at left guard in the third game of the 2011 season, and he maintained that starting spot for the next two seasons before switching to center during practices last December for the Trojans' appearance in the Sun Bowl.
He is the second USC player to announce his intention to leave school for the NFL. Safety Dion Bailey made his announcement Monday.