USC center Marcus Martin will enter the 2014 NFL Draft, making the announcement Friday morning on Twitter.
Martin, a 6-foot-3, 310-pound junior, started 33 games over the past three seasons while alternating between guard and center, but missed the Las Vegas Bowl win after dislocating his kneecap against UCLA.
Martin was one of two centers named first-team All-Pac-12, joining Hroniss Grasu of Oregon, who previously announced he would return to school next season. He was also recognized as USC's offensive lineman of the year.
Martin's departure represents a major blow to a thin front line that must already replace right tackle Kevin Graf and could lose guard Aundrey Walker to the draft. Lightly used redshirt sophomore Cyrus Hobbi returns next season, and versatile sophomore Max Tuerk could slide over from guard.
With Martin leading the way, USC averaged 172.8 rushing yards per game and scored 29.7 points per game this season.