Details on who the 59-year-old actor is playing are being kept under wraps, but an insider confirms that he'll first appear early into the long-running medical drama's upcoming tenth season.
While Remar's character remains a mystery, there are two things about the new season of 'Grey's" that have already been revealed.
It was reported earlier this week that original cast member Sandra Oh, who plays Dr. Christina Yang, will be leaving the series after this season.
Creator Shonda Rhimes also recently tweeted (and later deleted) a photo from the table read for the show's 200th episode that featured James Pickens Jr, which seems to indicate that his character Dr. Richard Webber survives his injuries from the Season 9 finale.
Remar has played Dexter's (Michael C. Hall) late father Harry Morgan in all eight seasons of the Showtime serial killer drama, which airs its series finale on Sunday, Sept. 22.
His other TV credits include "Wilfred," "Hawaii Five-0," "The Vampire Diaries" and "Sex and the City."
"Grey's Anatomy" returns for Season 10 with a two-hour episode on Thursday, Sept. 26 at 9/8 p.m. CT on ABC, while "Dexter" continues Sunday nights at 9/8 p.m. CT on Showtime.