Murray announced his decision to solely concentrate on the gridiron Monday on Twitter.
"Moving forward, I am committing my life and time to becoming an NFL quarterback," Murray wrote.
"Football has been my love and passion my entire life," Murray added. "I was raised to play QB, and I very much look forward to dedicating 100% of myself to being the best QB possible and winning NFL championships. I have started an extensive training program to further prepare myself for upcoming NFL workouts and interviews. I eagerly await the opportunity to continue to prove to NFL decision makers that I am the franchise QB in this draft."
The Oakland Athletics selected Murray with the No. 9 overall pick in the 2018 MLB June Amateur Draft. Murray was allowed to play his final season for the Sooners and won the 2018 Heisman Trophy.
NFL analyst Lance Zierlein wrote that Murray's NFL comparison is Seattle Seahawks quarterback Russell Wilson. Wilson was a 41st round pick by the Baltimore Orioles in the 2007 MLB June Amateur Draft. He was selected by the Colorado Rockies in the fourth round of the 2010 MLB June Amateur Draft.
The five-time Pro Bowl selection and 2014 Super Bowl champion has never appeared in a regular season game, but hit .229 with five home runs, 26 RBIs and 19 stolen bases in 93 games at the Short-Season A and Class-A level in 2010 and 2011.
"He's [Murray] a special athlete, but it takes more than that," an anonymous NFC team executive told NFL.com. "We just don't know with him because he's had one year in the Big 12 with a great system. I like him, but I wouldn't be ready to risk my job for him yet."
Murray received a $4.66 million signing bonus after being drafted by the Athletics. Oakland's pitchers and catchers report Monday, with the full squad joining them Saturday in Mesa, Ariz.
Murray hit .296 with 10 home runs, 47 RBIs and 10 stolen bases in 51 games this season for the Sooners. He also had a .991 fielding percentage and two assists. The multisport phenom also completed 69 percent of his throws for 4,361 yards, 42 scores and seven interceptions for the football team. Murray plowed for 1,001 yards and 12 scores on the ground during his junior campaign for the Sooners, before opting for the NFL Draft.