Joeckel -- 6-foot-6, 310 pounds -- was a consensus All-America this season and was awarded the Southeastern Conference's Jacobs Blocking Trophy, as the best blocker in the league. The Outland Trophy is symbolic of a player being considered the best interior lineman.
"This was a very difficult decision for me," Joeckel said Tuesday. "I have thought long and hard and visited with my family and coaches. I feel it is in my best interest to come out. I appreciate all that Texas A&M has done for me and my family.
"It is tough to leave a great group of coaches and players, including my twin brother Matt. I know they will have a great season in 2013 and I will remain their biggest fan."
Matt Joeckel is a quarterback at Texas A&M but behind Heisman Trophy winner Johnny Manziel on the depth chart..
Luke Joeckel started all 39 games in his career at Texas A&M, which finished the 2012 season 11-2 and ranked No. 5 in the nation.
"Luke is projected to be one of the top players selected in the overall draft," Texas A&M Coach Kevin Sumlin said. "We appreciate everything he has done for Aggie football and Texas A&M and wish him well in the NFL."