AceShowbiz -

"ER" aims it big for its final season wrap. Now that George Clooney is known to have appeared on the set of the show, the execs are splatting the icing of the cake by signing Susan Sarandon in. E! Online reported that the actress has filmed some scenes with Clooney late last week.

Sources are spilling that they filmed together at the Warner Studios in Burbank but no more details are given other than the info that the episode will air toward the end of the the current final season. It still remains a mystery though how Clooney's Dr. Doug Ross will contribute to the storyline but E! said that he shares at least one scene with Linda Cardellini who plays Nurse Samantha Taggart.

"He was charming," a crew member told E!. "Everyone had a great time with George, and he told some great stories about the old days. He really enjoyed himself and was glad he did it."

No rep has come out with an official statement to the guest appearance of both George Clooney and Susan Sarandon.