Speaking to TMZ, Novak said that Margera leaving rehab earlier took him by surprise, and now he's concerned that his friend and former co-star could try to take his own life if he doesn't stay in treatment.
Margera announced his plans to enter rehab around New Years Eve, writing in an Instagram post, "Off to alcohol rehab for the 3rd time. I am hoping the term 3rd time is a charm is true."
Previously, Margera had suffered an intense public meltdown that saw the skateboarder heavily criticizing many people in his life — with Novak being one of the main targets — while presumably under the influence of alcohol.
While in rehab, Margera took to rehab again to speak candidly about how the death of his best friend and fellow Jackass star Ryan Dunn was the biggest factor is his downward spiral into substance abuse.
"I have spent enough time grieving over Ryan Dunn through alcohol. I'm 39 years old, the party is over. I don't plan on drinking anymore," he wrote. "I have wasted too much time at the bad and all my friends who needed decades of help are now all sober. I would like to join the sober parade."
"I head the stories of other rehab patients telling me about there weeks or months of horrible detox. Well guess how many days of detox I had? ZERO!" he added in the post. "I am sick of people always thinking I'm drunk, crazy or f—ed up. So if you plan on calling me to tell me that, you can go f— yourself instead. I'm not going to suck anyone's d— to stay on element and or prove that I am sober, I am sober."
Margera captions that particular post, "Writing is one thing to do in rehab."
In a separate post, Margera wrote about his issues with rehab, saying, "I don't do well with not being allowed to Facetime my wife and kid…I don't do well with not being able to answer important calls with important people."
Subsequently, after only 10 days in rehab, Margera left, saying in an announcement, "I am not alone! I might not be in rehab with you, but I am surrounded by many sober family and friends, spiritual healers, therapist, sober coaches and my sponsor. I do not have a desire to drink because I have so much to do that being bored is out of the question. I don't want to drink anymore because it ruins my focus of what I know what I have to do and I am having a blast doing it."
At this time, Margera does not appear to have publicly responded to the concerns of his friends.