Smith, Nelson and Glo, along with Wentz were never the same after they went on COVID protocol. It isn't the only reason, but it is a reason. COVID seems to affect footballers in Europe for up to months. Stands to reason it can do the same for NFL players.
http://www.economist.com/graphic-det...ger-for-months
Having said that, every team dealt with COVID. We are the only one that collapsed