IRVING, Texas -- The official first day of the Dallas Cowboys' offseason program is April 18. Unofficially it has already begun.

A number of players have been working out at Valley Ranch regularly on their own.

“I know we have a team that I think likes to work the right way in the offseason, likes to work hard,” linebacker Sean Lee said. “That’s one problem we didn’t have last year. I thought we worked extremely hard. Now it’s time to turn that into production.”

Tony Romo tweeted Thursday that he will be ready for a full offseason and the organized team activities. The first OTA is scheduled for May 24. Last year Romo was able to take all of the snaps in the offseason for the first time since 2012.

The mandatory minicamp will be on June 14-16.

At the close of minicamp the Cowboys will prepare for the move to their new facility, the Ford Center at The Star, in Frisco, Texas. The Cowboys will practice full-time in Frisco upon their return from training camp in Oxnard, California in August.