According to TVLine's Kimberly Roots, Sean Hayes has been cast in a recurring guest-star role for season 2 of Up All Night. Here's an excerpt from the article, which gives some details on Hayes' role:
Will & Grace’s Sean Hayes will join the NBC sitcom’s upcoming second season as an accompanist who worked with Maya Rudolph’s Ava during her music recording days, TVGuide.com reports. His multi-episode arc will have him palling around with the audacious Ava front woman, whose show-within-a-show we’ll see far less of (according to The Huffington Post) as the comedy moves toward telling more stories about Reagan, Chris and Amy at home.
Hayes’ casting news follows word that Best Friends Forever’s Luka Jones is now an Up All Night series regular who’ll play the divorced younger brother of Christina Applegate’s Reagan.
Link to the full article:Up All Night Casts Sean Hayes -- Season 2 - TVLine