Add another brilliant guest star to The Big Bang Theory's roster. Hello Ladies alum Stephen Merchant has booked a guest role on an upcoming episode of the CBS comedy, The Hollywood Reporter has learned. Additionally, Manhattan Love Story grad Analeigh Tipton will also appear in a season nine episode.

While CBS has remained mum on who Merchant and Tipton will play, multiple reports that have surfaced following Tuesday, October 20's episode nine taping indicate both will appear in the episode and play dates for Amy (Mayim Bialik) and Sheldon (Jim Parsons), respectively. Worth noting that Tipton — a former America's Next Top Model finalist — previously guest starred and played herself during a previous episode.

Big Bang Theory showrunner Steve Molaro told THR at the start of season nine that producers planned to keep Amy and Sheldon apart "until the time feels right."

"Right now, the dynamic has been fascinating and interesting," he said. "We're seeing all new colors for both of them as well as the way it impacts the group. There's not a set plan — we're feeling this out along in same way Amy is."

Merchant and Tipton join a roster of Big Bang Theory guest stars including Bob Newhart, Billy Bob Thornton, Buzz Aldrin, Christine Baranski, George Takei, Katee Sackhoff, Leonard Nimoy, LeVar Burton, Sara Gilbert, Stan Lee, Stephen Hawking, Summer Glau and Wil Wheaton, among others.

The Big Bang Theory airs Mondays at 8 p.m. on CBS and will return to Thursdays after football.