Eric Dane played the character of Mark Sloan, who was introduced in Season 2 of Grey's Anatomy. In season 9, during the initial episodes, he was killed off due to some injuries from the season 8 plane crash. Later in the show, he had once again returned briefly in Meredith's COVID-19 hallucination alongside other deceased characters. However, the reason behind his exit has always been a mystery for the fans.
While speaking to Deadline, the actor reflected on his role and revealed that he did not choose to leave Grey's Anatomy. It was a studio-driven decision that made his character exit the show, while his prescribed addiction and expensive salary backed this decision. Read on to know more.
Why did Eric Dane exit Grey's Anatomy after Season 9?

Eric Dane's exit was a result of a decision taken by the studio, keeping in mind several factors. Dane has been struggling with prescribed drug addiction, which began post a sports injury.
"They didn’t let me go because of that, although it definitely didn’t help,” he explained to the Deadline.
His comment suggested that his prescribed addiction was a contributor to the situation, but not a major reason. There was more to it.
He stated that he has become way too expensive for the production. Dane had spent the most time on the show and had become a high-salaried cast member. This is the reason networks usually cut down long-term actors after a point to ultimately reduce costs.
“I was starting to become, as most of these actors who have spent significant time on a show, you start to become very expensive for the network. And the network knows that the show is going to do what it’s going to do, irrespective of who they keep on it. As long as they have their Grey, they’re fine."
Dane's character Mark is one of the best plastic surgeons in the world and a pioneer in reconstructive and cosmetic surgery at the hospital. The character shared a close relationship with Derek, being his childhood friend. However, when Mark's affair with his wife comes out, their friendship broke.
In the interview, the actor also said that he was no longer the guy the production had hired.
“I wasn’t the same guy they had hired. So I had understood when I was let go. And Shonda [Rhimes] was really great. She protected us fiercely. She protected us publicly. She protected us privately. … But I was probably fired. It wasn’t ceremoniously like, ‘You’re fired,’ it was just like, ‘You’re not coming back.'”
This incident reflects how some exits in the network happen quietly and without confrontation. He praised Shonda for the support and expressed that there was a time when he understood that he was the one who was leaving the show.
Therefore, we can say that the reason behind Dane's exit from Grey's Anatomy was basically him becoming too expensive for the production, along with his personal life dealing with prescribed addiction.