Groban has shared the screen with Piggy before, with a brief cameo in the Muppets' latest feature Muppets Most Wanted, and collaborating with the gang in a music video for his cover of "Pure Imagination" with Lindsey Stirling earlier this year.
Is it possible the two will kindle their relationship on the set of Up Late with Miss Piggy?
Groban has previously guest-starred on Parks and Recreation, CSI: NY and parodied himself on Glee. He joins a guest of celebrity Muppets guests that includes Liam Hemsworth, Reese Witherspoon and Imagine Dragons.
The Muppets premieres Tuesday, Sept. 22 at 8/7c on ABC.
Video: Check out The Muppets' pilot presentation