Sha’Carri Richardson sent a message before she returned to the track on Saturday.

“Aug. 21,” she wrote alongside a video she posted on Instagram this week, “and I’m not playing nice.”

The message was clear: Weeks after a positive drug test cost her Olympic dream, Richardson was, in the video and in real life, ready to run again. On Saturday at Hayward Field in Eugene, Ore., though, her return to competition at the Prefontaine Classic did not go as planned.