Cooper Kupp had achieved greatness with the Los Angeles Rams during his eight seasons with the team. The issue was that he had passed 30 years old and had a number of years where he wasn't able to play a full season due to injuries. Maybe he was done. The Seattle Seahawks didn't think so.
The Rams, according to Michael Silver of The Athletic, "urged" Kupp to retire. That seems rather rude, however. Los Angeles knew they didn't want to pay the wide receiver anymore, but they didn't want to simply release him and look bad, either.