Grey's Anatomy is bringing back one of its original and most controversial stars.

Isaiah Washington, who originated the role of Dr. Preston Burke on the ABC medical drama, will return to reprise his role on the Shonda Rhimes and Betsy Beers medical drama, The Hollywood Reporter has learned.

PHOTOS: 'Grey's Anatomy's' Famous Departures

Washington will return to guest star for a May episode of the medical drama seven years after he was fired from the series following on-set clashes and anti-gay remarks directed at then-closeted co-star T.R. Knight.

His return to the series comes as Grey's is preparing to say farewell to one of its original and most beloved stars, Sandra Oh, whose Cristina was at one point engaged to marry Washington's character. Oh will exit Grey'sfollowing the end of its current 10th season in May.

"It's important to me that Cristina's journey unfolds exactly as it should," showrunner Rhimes said in a statement. "Burke is vital to that journey -- he gives her story that full-circle moment we need to properly say goodbye to our beloved Cristina Yang."

PHOTOS: The Couples of Shondaland: 'Grey's Anatomy,' 'Private Practice,' 'Scandal'

Washington's casting comes a year after the actor was cast in The CW's The 100, marking his first series regular role since he was famously ousted from Grey's. Following his controversial remarks, which drew the ire of LGBT-friendly Rhimes and the cast as well as LGBT organizations, Washington apologized for his comments, calling his behavior "unacceptable in any context and commending Knight for his courage after he was forced to come out. The actor in 2008 also filed a complaint with SAG over ABC's use of his image on Grey's Anatomy, when Burke's photo was featured in a "newspaper article" about the character receiving a prestigious surgeon's award in a May 9, 2008, episode. Burke has been sporadically mentioned in the years since.

In an October interview with THR celebrating the show's 200th episode, Rhimes said the aftermath of the Washington flap was a "really difficult time." It was hard for me to write the show. Seasons four and five were difficult because I was in a dark place after the press frenzy that descended on us because of the [Washington and Knight situation and critical backlash to the stories]," she said. "In the beginning, it felt like such a magical place, and to discover that everyone isn't who you thought they were is very unfortunate. Some awesome things did come out of it though. I found the Callie [Sara Ramirez] and Erica [Brooke Smith] relationship and Owen [Kevin McKidd, Oh's most recent love interest] in there. There were things that were amazing because they pull you through. A lot of us joke that we have PTSD from that period of time -- and we do."

PHOTOS: On the Set of 'Grey's Anatomy's' 200th Episode

Burke was last seen during the third season finale, when he stood Cristina up at the altar on their wedding day. After she returned to their home, Burke had left everything save for a few personal items, leaving Cristina devastated.

UPDATE: LGBT watchdog group GLAAD praised Washington's return to the series. "His PSA and his statements promoting marriage equality in recent years have sent a strong message of support for LGBT people," GLAAD said in a statement, praising the actor for his role in out director Patrik Ian-Polk's Outfest Fusion film Blackbird. "We look forward to seeing him return to one of our favorite shows, as well as in Patrik-Ian Polk's moving film Blackbird about a young man coming out in a small Southern town."

Grey's Anatomy airs Thursdays at 9 p.m. on ABC. A specific date for his guest turn has not yet been announced.

Email: Lesley.Goldberg@THR.com

Twitter: @Snoodit