Ohio State defensive end Nick Bosa has been planning for some time now to enter the 2019 NFL Draft. Although he has not formally entered his name into the draft (as far as I know), he crossed the proverbial Rubicon. Bosa signed with CAA to handle his contract negotiations, per Pro Football Talk. By signing with an agent, Bosa foregoes his remaining eligibility.
This is not a shocking development. In October, while rehabbing a core muscle injury, Bosa announced he would not return to the university once healthy. He has instead spent his time since then rehabbing and furthering his preparations for the 2019 NFL Draft.