Jason Alexander (search) isn't worried about whether his new CBS sitcom "Listen Up" (search) will achieve the success of "Seinfeld." In fact, he says you can't compare the two.

"What happened with that TV show is a once in a lifetime thing," he told AP Radio recently. "To compare it to anything else is truly apples and oranges. I understand the comparison because they were both on TV screens, but that's about where the comparison would have to drop."

Alexander, who played the hapless George Costanza on "Seinfeld," (search) is aware of the pressure on him to star in a popular show, but he said it's nearly impossible to create the same type of buzz.

"Seinfeld wasn't a TV show, it was a phenomena," he said. "I think there's an expectation from the critical community that whatever we do have that same immensity to it, to become a phenomena, and I don't know how any of us can possibly live up to that."

Seinfeld aired on NBC for 8 years. The 1998 finale was watched by 76.3 million people. Co-stars Julia Louis-Dreyfus (search), who played Elaine, and Michael Richards (search), who played Kramer, have both starred in post-Seinfeld sitcoms that have failed.

"Listen Up" stars Alexander as a sports talk show host and who struggles to get the respect and admiration from his family that he gets from his fans. It is based on the writings of real-life sports commentator and columnist Tony Kornheiser, and debuts this fall Mondays at 8:30 p.m. EST.