Arians mentioned a couple things. One: He likes his guys! UDFA Cam Gill who we never heard of until he was announced to have made the final roster. And castoff LB Quinton Bell. Those are special teamers. Not meant to actually play a meaningful snap. But Bruce likes those guys! Who needs Matthews?
Two: The financials. That is the real reason. This is from an article on NFL.com:
"We recently had communication with the Broncos, as we have with other teams during the offseason," Williams said in the statement. "We were under the impression that communication would remain private, but since it did not, let me be clear: We were unable to come to an agreement with Denver, but Clay remains open to playing in the NFL in 2020, provided it's the right opportunity for him and his family."
Perhaps Denver wasn't where Matthews wants to play in 2020. More likely, John Elway wasn't offering enough money to entice the veteran linebacker.
The Los Angeles Rams cut Matthews earlier this offseason but still owe him a $2 million bonus. Any deal he signs would offset portions of that $2 million. So, if the Broncos – or any other team -- weren't offering more than $2 million, he'd essentially be playing for free.
Matthews is already making $2 mil for doing nothing. H'es going to need a significant bump from that to get back on the field. So the Bucs would also have to offer Matthews about $4 or 5 mil for them to even pick up the phone and start bargaining. That's why Clay Matthews isn't playing for the Bucs. The Broncos can't pay him and they just lost their starter. The Bucs sure aren't going to have that kind of cap space to spend on a backup. That's the financials Arians is talking about.
So if you had the hope that Clay Matthews is still out there and the Bucs might scoop him up, you might as well stop holding your breath.