The 30-second video is based largely around Meredith (Ellen Pompeo) and the consequences of her decision to tamper with Derek's Alzheimer's trial.
Alex (Justin Chambers) is also criticised by his colleagues for bringing Meredith's behaviour to light.
Elsewhere in the trailer, Cristina (Sandra Oh) is shown reacting to the news of her pregnancy.
Previous reports have revealed that the new season of Grey's Anatomy will pick up just days after the last episode.
The show's executive producer Shonda Rhimes has also insisted that this will not be the final season despite rumours that Pompeo and Patrick Dempsey could leave next year.
Grey's Anatomy will return with a two-hour premiere on September 22 on ABC.
Watch the trailer for the eighth season of Grey's Anatomy below (may contain spoilers):