Derek Carr on Michael Thomas’ tweets

I'm pretty sure once the team season is over with... It's immediately the off-season and they can makes moves to cut or extend players. Even though most players like to wait till FA period to do it.

I'll have to look it up.
Just reserve/futures stuff for now.
Here’s a 2013 Bleacher Report article about that process. Little, if any has changed since then:

Reserve-Futures Contracts