The 64-year-old actor and 42-year-old actress, who played dad and daughter Dan and Darlene Conner on the ABC sitcom, spoofed the series on Gilbert's talk show, The Talk.
Goodman and Gilbert staged a scene where Darlene "came out" to her father as a talk show host. In real life, the actress came out as lesbian in 2010.
"So there's something I've been wanting to talk to you about for a while now," she said as Darlene. "I don't know how to say this... I'm a talk show host."
"Well, as long as you're happy, you know, me and your mom will support you," Goodman responded as Dan. "You know, for a minute there, I thought you were gonna tell me you were gay."
"Let's save something for halftime," Gilbert said.
Roseanne had a nine-season run on ABC from 1988 to 1997, and ended with Dan dying in the series finale. Goodman said on The Talk that he'd be open to an official reunion despite his character's passing.
"Oh, hell yes!" the actor said. "[Roseanne Barr] and I did a pilot about five years ago that didn't go anywhere ... We were very happy to work together. I talk to her every once in a while. If we could get everyone together... there's such a wealth of opportunity."
"I would [also be interested]," Gilbert added. "Your only fear is you don't want to do a bad version. You don't want to damage what's been done. I think it'd be amazing."
Goodman previously reunited with Gilbert on The Talk in 2014. He said at the time that Gilbert, Michael Fishman and Lecy Goranson, who played Darlene, D.J. and Becky Conner, "were like [his] own kids" during Roseanne's run.