TR Knight TR Knight

Grey's Anatomy alum T.R. Knight has signed on to co-star in 42, the Jackie Robinson biopic from Legendary Pictures, according to The Hollywood Reporter.

Knight, who played George O'Malley on the ABC medical drama, will portray Harold Parrott, the Dodgers' traveling secretary. As previously announced, Chadwick Boseman will play the legendary baseball star, while Harrison Ford will play Branch Rickey, the Dodgers executive who signed Robinson to the team.

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Directed by Brian Helgeland, the film will be executive-produced by Thomas Tull, Jon Jashni and Dick Cook.

42 marks Knight's first film since exiting Grey's Anatomy at the end of Season 5. Last year, he appeared on an episode of Law & Order: SVU.