John Mulaney has already checked himself into rehab. It is not clear what exactly triggered the decision, but the move made friends and family happy because he is prioritizing his health. 

John Mulaney Rehab: There were Signs? 

According to a new report, fears over John Mulaney's mental state has already started as early as the time he made an appearance in "Late Night with Seth Meyer."

His behavior at that interview was noticeably weird and bizarre, triggering fears that he was again once more dealing with sobriety issues.

Turns out his fans were right.

John Mulaney SNL: Comedian "Late Night" Rambling Concerning 

On that episode, Mulaney was wearing dark glasses and made some surprising comments about Prince Harry and Meghan Markle.

He called Prince Harry a "dumb ginger" and tagged Meghan Markle as a "silly goose."

In the "Late Night" clip, posted to YouTube on November 24, Mulaney can be seen hosting a fake "Royal Watch: News from the Real-Life 'Crown'" segment, where he thrown in one joke after another about the royaals.

The comedian, who as Page Six exclusively reported already checked into rehab for both cocaine and alcohol addiction, joked that the Duke and Duchess of Sussex were annoyed by COVID because it took all the media attention away from their so-called stunt, or Megxit. 

The jokes were not that weird since the same allegations were being made by many tabloids and media outlets, but how Mulaney appeared on this show made some fans worry.

He was wearing a rumpled, oversized coat and sunglasses, both gifts from Julian Casablancas of the Strokes, who performed on the "Saturday Night Live" episode that Mulaney hosted back in October.

He then said Harry was "the real dunce of this fairytale ... You dumb ginger, don't leave your title just because you don't like your 94-year-old grandma."

He added, "That's the definition of something you wait out, gangsta. I am pretty sure father time is going to sort out the case of the very old bummer woman who had 30 months to live." 

He then caught himself and said, "Ahh, too mean." 

After Meyers raised the topic of of Princess Diana's death, Mulaney took off his sunglasses, which triggered more concern. He had dark, bleary eyes, making people wonder if he was alright. 

He then said, "You know it's weird, right, that Meghan and Harry left?" 

He added, "You thought rolling with those dorks in church clothes would be fun? Had you been told it was non-stop laughs? Because you're thinking of 'The Munsters,' you silly goose."

He then continued his monologue, no longer caring if Meyers or the audience can truly understand him. 

"Just the fact that she wanted to leave the royal family because they were like 'be proper and sit still' ... So don't marry into the family with the most jive-ass boring people ever and then be like, 'Oh, shall we play Never Have I Ever?," he added, now at the point of prattling on and on.  

John Mulaney Rehab Overdue? 

Meyers was obviously getting confused by the minute so at the end of Mulaney's rambling speech, Meyers made a counter-joke to clear the air. 

"I love having you on here, but in the future, if you just want to talk things like this out, a phone call might be better ... We will see what of this we can use, but it might be online only." Sounds half-meant though. 

Nobody spoke of the Seth Meyer appearance, chucking it to the fact that he just made some jokes that people found hard to catch up on.

However, when they heard that Mulaney has entered rehab, they are now recalling this episode and how weird the SNL comedian acted.

One viewer on Twitter said, "If you've watched @sethmeyers lately you had to know something was up." 

Another wrote, "Three weeks ago I felt there was something seriously *off* with John Mulaney's appearance on Seth Meyers."

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