The Glee alum was spotted filming a scene with star Justin Chambers on Friday -- the same day Morrison teased on Instagram that his next role is a character named Dr. Paul Stadler (all without ever saying the phrase "Grey's Anatomy," of course). [...] while neither ABC nor Morrison have yet to officially confirm the news, TVLine reports that not only is Morrison joining Grey's as a new doctor, but he's actually playing Jo's (Camilla Luddington) estranged husband! [...] Jo's terrifying ex has only been discussed, but never seen...