MESA, Ariz. (CBS13/AP) — Oakland Athletics prospect Kyler Murray is committing to football instead of baseball, the athlete announced on Twitter Monday morning.

“Moving forward, I am firmly and fully committing my life and time to becoming an NFL quarterback,” a caption in a picture Murray posted to Twitter reads. “Football has been my love and passion my entire life. 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.”

Kyler Murray’s locker remained empty on Monday in the spring training clubhouse of the Athletics, who said they were uncertain when or if the Heisman Trophy winner will report to the baseball team he signed with last summer.

Billy Beane, Oakland’s executive vice president of baseball operation, said talks were continuing with Murray. The outfielder was selected ninth overall last June and agreed to a minor league contract that included a $4.66 million signing bonus.

“Things have certainly changed since the draft,” Beane said Monday. “The situation is fluid right now and based on a historic college football season that the young man had.”

The A’s start full-squad workouts Saturday, a day after their position players report.

“I don’t have any answers for you, and I probably won’t until we’ve decided on the process,” Beane said. “All I can tell you is it hasn’t been decided and the conversations will continue.”

Beane would not reveal a timeline in regards to making a decision about Murray’s future. The NFL combine begins Feb. 26.

Murray’s baseball deal called for him to receive $1.5 million within 30 days of the deal’s approval last summer by Major League Baseball and $3.16 million on March 1. If he doesn’t play baseball, Oakland would get back the money it already has paid and not have to give Murray the remainder.

Bo Jackson and Deion Sanders played both football and baseball, but Sanders was a running back and Sanders a cornerback.

“Quarterback is a very demanding position, as is being a Major League baseball player,” Beane said. “To say somebody could or couldn’t, I’m not here to say that. Something like that is something that is part of our private discussions.”

Copyright 2019 The Associated Press.