The statement was reminiscent of the "I don't know her" shade made famous by Mariah Carey, who first used it when asked in a German TV interview about Jennifer Lopez in the early 2000s, before going on to be immortalized in GIF and meme format.
The "Thelma and Louise" star was addressing her feud with her "Will & Grace" rival in an interview on Thursday with Us Weekly when she unleashed the infamous put down -- albeit clearly unintentionally.
"I don't know what I would gain from that," she replied when asked if she would ever try a sit down with Messing. "I don't really know her."
"There are a lot of people who find it really funny," Sarandon said of the feud. "I don't take it very seriously. Sometimes it will be very quiet for a while, and then all of a sudden, I'll be wondering, 'Gosh, I wonder what led to that?'"
Susan, of course, knows full well what led to that. Ironically, the two women are actually united in their hatred for one thing: Donald Trump.
The problem is, they backed two different (and ultimately unsuccessful) candidates to go against him. Susan is a fervent Bernie Sanders supporter, while Debra is with Hillary Clinton.
Their beef all started in 2016, when in an interview with MSNBC, Sarandon said she wasn't sure who she'd vote for between Hillary and Trump; claiming that choosing Trump might bring about a preferable "revolution immediately".
Messing slammed her on Twitter: "Susan Sarandon muses tht Trump prezcy wud b better 4 the country thn Hillary.Wonder if she'd say that if she were poor,gay,Muslim or immgrnt."
"What kind of revolution?! A WALL?! #ImWithHer but if it's Bernie/Trump I will ABSOLUTELY support BS. the idea that Susan Sarandon wud say that NOT supporting Hillary in a HRC/Trump race is a legitimate choice for Democrats, is insane."
Sarandon fired back on Twitter: "Watch the interview. Don't just read the headlines. #Spin." before the two got into a heated back and forth on Twitter.
Things flared up again last year when after another interview with Variety, the publication tweeted out the headline: "Donald Trump has, if anything, inspired more women and people of color to run for office, says actress Susan Sarandon."
STFU SUSAN. Oh yes, PLEASE let's give Trump CREDIT. I mean how else are you able to walk out on the street. Convince yourself that that this CATASTROPHE of a President who you said was better that HRC IS NOT ripping children away from parents seeking asylum, holding children https://t.co/UuXLLdahaB
"STFU SUSAN," Messing tweeted. "Oh yes, PLEASE let's give Trump CREDIT. I mean how else are you able to walk out on the street. Convince yourself that that this CATASTROPHE of a President who you said was better that HRC IS NOT ripping children away from parents seeking asylum," she began, before listing all the President's perceived crimes.
"you were dead WRONG running around bellowing that HRC was more dangerous than Trump. Only a self righteous, narcissist would continue to spout off and not - in the face of Americans' pain and agony -be contrite and apologize for your part in this catastrophe. But, you do you Susan."
Again, Sarandon clapped back, accusing Messing of jumping on "clickbait" headlines without checking the facts.
"Debs, before you get yourself all self-righteous try clicking on the video and listening to what I actually say," she snapped.
Earlier this year, Messing fired another snarky shot, tweeting: "Hey Susan Sarandon, how are you liking the revolution?"
Sarandon expertly parried by replying with a list of the "radical" social causes Bernie was fighting for, and invited her rival to join.
Happy so many ideas labeled impossible/radical in 2016 like Medicare 4 All, fighting climate change, $15 min wage & tuition free college are now mainstream & supported by majority. Racial, economic & social injustice must be addressed with systemic change. You're welcome to join. https://t.co/7cX5qvxweY pic.twitter.com/dUdd8cm5v3
Just this month, Messing told Andy Cohen on "Watch What Happens Live" she would rather be stuck in an elevator with Donald Trump than Susan Sarandon, as at least with the former she could try to inspire "some policy changes."
Speaking to US Weekly this week, Sarandon elaborated on how she deals with trolls who criticize her political beliefs
"My feeling is, anybody that's not in the fight getting bloodied themselves, I don't really care what they say," she said. "First of all, I don't read most of them because I'm not on social media that much."
"If it's someone that has a huge following and they're tweeting misinformation, then sometimes I'll just say, 'You know, I appreciate your passion. It will be great if you can lend that voice to something,' and then I'll use their side to put out the correct information, but I don't get into personal things," she added. "I don't see the point of it, really."