A year ago, the Raiders' defense ranked 22nd, but they were young, fast and athletic, and the thinking was that the group would make a huge leap in 2017. It didn't happen, and through 10 games -- including last Sunday's 33-8 blowout loss to the Patriots -- the Raiders had the league's worst defense, according to Football Outsiders' metrics.

And that reality goes a long way in explaining this one: On Tuesday, the Raiders fired defensive coordinator Ken Norton. It was a perfectly understandable move, though apparently not one fully embraced by Norton's players.

Minutes after Norton's firing became public, Raiders linebacker Bruce Irvin tweeted "BULLS--T." A day later, Irvin and defensive end Khalil Mack missed practice for reasons that weren't injury related. The team said the players were given a "rest day," but as ESPN.com's Paul Gutierrez notes, Irvin hadn't previously missed a practice all season and it was Mack's first absence since Week 1.

So were the missed practices a means of protesting Norton's dismissal?

"I like to keep my thoughts private," Mack said, via Gutierrez.

Irvin added: "Nah, I ain't talking, bruh. You know I ain't talking about that today."

When asked if his tweet was related to Norton's firing Irvin shrugged before moving on.

Norton's relationship with his players aside, it's hard to overlook just how bad the Raiders defense has played this season. The unit has yet to intercept, which goes a long way in explaining their last-ranked pass defense (they're 21st against the run, so there's that).

"We're going to focus on the process," Del Rio said of the defense moving forward. "I think one thing that's maybe gotten away is the focus on winning. We need to win, we need to win, we need to win. Yeah, everybody needs to win. Everybody wants to win. For me, it's about the process ... recover, prepare, compete."

If it's any consolation, the defense isn't the only reason the Raiders are 4-6, in third place in the division and 13th in the playoff race. Dumb mistakes and poor execution on both sides of the ball have played a starring role in a disappointing 2017 season.