Grey's Anatomy showrunner Krista Vernoff has revealed new details about Alex Karev's exit storyline.

Justin Chambers announced last month that he would be leaving the long-running medical drama after 15 years. His final episode has already aired. And Vernoff addressed Alex's exit from Grey Sloan Memorial - and Pac North - in a recent interview with Variety.  It was a very careful threading of a needle, where we are giving a little bit of information and pain to Jo,” she said. “We’re, episode by episode, illuminating the story of where Alex is. And it takes us quite a few more episodes to get there and to give the audience clarity.” She admitted that Alex's exit was complicated, following the difficult time his wife Jo had gone through last season and her fight to get to a better place emotionally. “Jo went through so much pain and so much grief just last season that I wanted to be careful,” she continued. “And so it’s a bit of a mystery [what’s going on with Alex], so that we don’t watch Jo in the same place that we watched her in last season. We did it as carefully as we could. But it takes a while to get there.” Justin Chambers left Grey's Anatomy fans stunned when he announced he was leaving the show in early January. “There’s no good time to say goodbye to a show and character that’s defined so much of my life for the past 15 years,” he said in a statement to PEOPLE  at the time. “For some time now, however, I have hoped to diversify my acting roles and career choices. And, as I turn 50 and am blessed with my remarkable, supportive wife and five wonderful children, now is that time.” He went on to thank Grey's Anatomy creator Shonda Rimes, as well as Ellen Pompeo,  Chandra Wilson and James Pickens - the three remaining original cast members. “As I move on from Grey’s Anatomy, I want to thank the ABC family, Shonda Rimes, original cast members Ellen Pompeo, Chandra Wilson and James Pickens, and the rest of the amazing cast and crew, both past and present, and, of course, the fans for an extraordinary ride.”