Gerard Butler Table for One

2/25/2012 11:25 AM PST

Gerard Butler -- Out of Rehab, Table for One [PHOTO]

After three weeks in treatment for substance abuse at the Betty Ford Center, Gerard Butler was seen out yesterday ... having lunch by himself in Malibu.

As TMZ first reported, Butler developed a problem with pain medication following filming for his breakout role in "300." The problem returned when Butler was injured on December 18 while shooting the movie "Of Men and Mavericks."

Butler left rehab yesterday, with his manager releasing a statement that read, "Gerard left Betty Ford early this morning and he's healthy."