09/21/2008 AT 02:00 PM EDT
Even four years after Friends
folded, Jennifer Aniston
's sitcom timing remains as razor-sharp as ever, as the Emmy-nominated cast of 30 Rock
will attest now that Aniston has shot her guest appearance for the NBC show.
"It was really fantastic. It was impressive. We were all taking notes," Jack McBrayer, who plays the air-headed Kenneth the Page told PEOPLE about Aniston's performance while he was attending Entertainment Weekly
Aniston, 39, comes to 30 Rock
in the role of a stalker
obsessed with Alec Baldwin's Jack Donaghy.
"I think we are all star-struck with her," said McBrayer, 35, who said the cast felt some butterflies in their stomachs on the actress's first day, but her sunny disposition quickly put them at ease.
"She was an absolute delight," he said. "She's such a pro, and she was just so lovely to be around."
McBrayer – who suggested that the door was left open for Aniston to make a return visit to the show – didn't get to trade any on-camera quips with Aniston for the third-season episode, but he was thrilled to share one scene with her.
"We don't necessarily interact," he said, "but you'll see me in the background."
Off-screen, he fared even better. "I got a picture taken with her, so that's all I needed."