The duo will both appear in the FX comedy's Thanksgiving episode, Entertainment Weekly reports.
Silverman will star as the sister of Andre (Paul Scheer), while Goldblum will play the father of Ruxin (Nick Kroll).
The League's co-creators Jeff Schaffer and Jackie Marcus Schaffer explained that Silverman and Goldblum are "funny and fearless enough" for the roles.
"And they didn't flinch when we told them all of the crazy things they'd be doing with our cast," they joked. "Fools!"
Seth Rogen recently starred in the season premiere of The League, which continues on Thursdays at 10.30pm on FX.
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