This Oct. 20, 2012 photo released by NBC shows Jason Sudeikis portraying Republican presidential candidate Mitt Romney, left, and Jay Pharoah as President
This Oct. 20, 2012 photo released by NBC shows Jason Sudeikis portraying Republican presidential candidate Mitt Romney, left, and Jay Pharoah as President Barack Obama in a skit from "Saturday Night Live," in New York. After eight years on the air at "Saturday Night Live," Sudeikis says he's calling it quits. (AP Photo/NBC, Dana Edelson)

NBC entertainment chief Bob Greenblatt seems to have a simple mantra in dealing with "Saturday Night Live" turnover: Keep calm and trust Lorne Michaels.

"'SNL' goes through these upheavals every year to some degree and every few years to a larger degree. Lorne's been doing this, what, 38 years now?" he said at a Television Critics Association panel Saturday.

In the latest "SNL" reshuffling, Jason Sudeikis said this week he would leave after eight seasons. He joins departing castmembers Fred Armisen and Bill Hader. Seth Meyers will leave this coming season to take over NBC's "Late Night," and Kristen Wiig and Andy Samberg left last year.

Greenblatt (pictured with Jimmy Fallon and Michaels in January) noted that turnover has been an issue since the show's original Not Ready for Primetime Players.

"He had the greatest first cast ever, and then, suddenly, they all moved on," said Greenblatt. "And then he had the greatest second cast ever."

That second sentence is open to debate. Michaels left the show in 1980, and much of the original cast and writing staff went with him. Jean Doumanian took over, leading the show through a very rough sixth season. The show picked up with the addition of Eddie Murphy, and Michaels returned in 1985.

"He's really good at re-seasoning this season," Greenblatt said. "Would we have preferred to keep Jason and Bill and Fred and Kristen for more time? Absolutely. Seth Meyers is going to leave to do his own new show for us. But some of these people have been on the show, in Seth's case, 12 years.

"They have families and lives and Bill wanted to move his family to the West Coast," Greenblatt said. "Movies come a-calling. You hold on to them as long as you can but nobody's better at combing this country and finding the next generation of these actors than Lorne."

He added: "He was the one who said Conan O'Brien should have his own show. He was the one who said Jimmy Fallon should have his own show. Tina Fey. The list goes on and on."