The Supernatural actress confirmed her participation via her Twitter account, but did not reveal any details about her role.
"I want you all to be the first to know I am a part of a new pilot for FX called Powers," she wrote.
Tal played Jo Harvelle on Supernatural between 2006 and 2009, and also starred in Veronica Mars.
Her recent television credits include guest roles on The Defenders, Pretty Little Liars and The Killing.
The Powers pilot, based on the comic series by Brian Michael Bendis, will follow homicide detectives Christian Walker and Deena Pilgrim as they investigate crimes committed by super-powered criminals.
Jason Patric and Lucy Punch will play the lead roles of Walker and Pilgrim. Charles S. Dutton will also appear as police department head Captain Cross in the pilot, with child actress Bailee Madison playing Walker's young ward Calista.
Powers will begin filming this summer in Chicago.
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