News of Osbourne's departure came a few weeks after a heated exchange between Osbourne and Underwood, in which Osbourne expressed support for Piers Morgan after he left "Good Morning Britain" over differing opinions about Meghan Markle following the Duchess of Sussex and Prince Harry's bombshell interview with Oprah Winfrey.
In addition, the intense discussion led to a subsequent internal investigation and hiatus from air before Osbourne ultimately stepped away from the show.
Now, during an April 3rd episode of her "Sheryl Underwood Radio" podcast, Underwood has opened up about the moment.
"Sometimes in life, something happens and you go, ‘Gosh, if I just would’ve … ‘There’s nothing I could have ‘just would’ve’ — this was going to happen, out of my control," Underwood, 57, said. "Sometimes you don’t want to know what you know."
Since Osbourne left the show on March 26, Underwood revealed that the two have yet to speak and when asked if Osbourne had reached out to her directly to apologize, Underwood quickly retorted, "no" before scrolling through her previous phone history to double-check.
However, Osbourne took umbrage with Underwood’s claims that she hadn’t apologized and shared alleged proof to the Daily Mail in the form of screenshots that the conversation had in fact gone down.
"I not only sent these messages to Sheryl but I apologized to her in person in her dressing room," Osbourne told the outlet on Tuesday. "Why are you saying I never apologized Sheryl? What are you trying to do to me?"
Osbourne continued: "Why are you trying to destroy my reputation? Just be honest. Tell me."
In the alleged conversation between the embattled hosts, Osbourne writes in a message dated March 12 -- two days after the on-air spat -- that her heart is "heavy" and she is "deeply saddened by the events that transpired on Wednesday."
"I don't want to lose my true friend over this," Osbourne allegedly continues. "Im sorry for telling you to f--k off during break, I'm sorry for accusing you of fake crying while we were live on air and I'm sorry for losing my temper with you."
Osbourne reportedly goes on to write that she "felt shocked, scared and saddened by what [she] felt like was a blind sided attack."
"You know me. You know how I've always had your back," Osbourne allegedly pleaded. "We've outlasted everyone on this show and that's because we've always been a team and had each other's backs. "
Osbourne then allegedly writes that she considers Underwood a "genuine friend" before supposedly extending an olive branch to the funnywoman to "talk on the phone over the weekend" if Underwood wanted to. "I'm here. Once again from the bottom of my heart I'm sorry."
Osbourne allegedly presses Underwood further: "Is there anything You need from me or that I can do to help you heal? Love and respect always - Sharon."
Per the Daily Mail, that message had gone unanswered for three days before Osbourne sent a follow-up text message, dated March 15 at 1:45 pm.
"Hi Sheryl. I know you're taking space and I don't want to disrespect that," Osbourne allegedly penned. "I'm just reaching out because I want you [to] know I'm thinking about you. If you are willing, can we talk before Wednesday? Big kiss."
Another three days supposedly passed before Osbourne hit send on another text on March 18 at 4:32 pm: "Sheryl I am thinking about you. Hope you are well. Sending my love."
During Underwood's three-part podcast episode titled, "Sharon Walks Away," the comedian said that when Osbourne, 68, joined the popular daytime talk show in 2011, Underwood had "heard things" about the former reality star – but maintained that instead of taking what she was being told at face value, she elected to get to know Osbourne and the two became "fast friends."
"I automatically just fell in love with her because I just like her. And I heard things and I was like, 'They got nothing to do with me.' My thing is I'm going to get to know you first," said Underwood.
Added the actress: "I had heard things, and I got phone calls of this and that and so what I said to those people, I said, 'Thank you for the information.' Because listen, in this business you've got all types of personalities, right?"
Despite the very public fallout, Underwood said she still "loves" the Osbourne family "from what I’ve known of them."
Underwood said she doesn’t believe Osbourne is a racist and is "disappointed" with the way things played out.
"I don't know anything other than what I've experienced with them, and this thing that has happened is disappointing to me."
"And maybe people don't want to hear me say, 'I still love the Osbournes.' I'm not saying I liked being treated the way I was treated," she added. "I'm very disappointed. And I'm just trying to navigate my feelings about that because it was a trauma."
On March 26, it was revealed that the former reality star "decided to leave" the long-running daytime talk show, according to a statement from CBS and obtained by Fox News at the time.
"The events of the March 10 broadcast were upsetting to everyone involved, including the audience watching at home," CBS' statement said.
It continued: "As part of our review, we concluded that Sharon’s behavior toward her co-hosts during the March 10 episode did not align with our values for a respectful workplace. We also did not find any evidence that CBS executives orchestrated the discussion or blindsided any of the hosts."
In a statement to Fox News on Tuesday, Osbourne's rep said: "Sharon stands by her remarks."
Reps for Underwood did not immediately respond to Fox News' request for comment.