Dane voluntarily checked himself into the Los Angeles area facility but is expected to return to work next week, according to a spokesperson.
In a statement to People, his rep said: "Eric Dane voluntarily checked himself into a treatment facility to help him get off of pain medication that he was prescribed for a sports injury that he suffered over the recent hiatus."
The spokesperson added that Dane will "report back to work" next week, saying: "Business as usual."
Dane plays Dr Mark Sloan in the ABC medical drama, which returns for its new season on Thursday, September 29. He has also appeared in movies including Valentine's Day and Marley & Me.
Dane and actress wife Rebecca Gayheart welcomed their first child together, a daughter called Billie Beatrice, in 2010, and are currently expecting their second. They married in 2004.
Neither Dane nor Gayheart has directly commented on the rehab report.
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