Mario Williams, Byron Maxwell Called Out by Dolphins DC Vance Joseph

Miami Dolphins defensive coordinator Vance Joseph made candid comments about defensive end Mario Williams and cornerback Byron Maxwell as he looks for answers following the unit's early-season struggles.

Williams has registered just one sack during the team's 1-4 start after signing a two-year, $17 million contract in the offseason, per Spotrac. 

James Walker of ESPN.com passed along Joseph's pointed remarks about the 31-year-old's lack of production.

"He's got to play harder; he's got to play better," Joseph said. "Obviously, he's being allowed to rush the passer. But the games we've been in, it's been more run-first, pass-second games. So for us to be a great rushing team, we have to earn the right. ... If they want to rush more, stop the run more consistently."

Questions about the four-time Pro Bowler's effort are not new. They were raised last season, when he tallied just five sacks in 15 contests for the Buffalo Bills, who released him in March. He also publicly raised concerns about his role in Buffalo head coach Rex Ryan's defense.

Matthew Fairburn of NYup.com noted the outspoken Ryan took a verbal shot at Williams when discussing the success of NFL sack leader Lorenzo Alexander on Monday.

"He's great with his teammates; he communicates extremely well," Ryan said. "Whether you rush him from an inside spot, an outside spot, wherever. He continues to do a great job. He drops. I don't recall him ever bitching about dropping. ... He's smart enough to know what we're trying to get accomplished."

Meanwhile, the Dolphins' acquisition of Maxwell from the Philadelphia Eagles is on track to be a bust, too. He's struggled in coverage and with tackling, which led to a one-game demotion.

"He has not played overall well," Joseph said, per Walker. "He's a guy that's here every day. He's working hard. He studies a bunch of film, but it has not come together for him. But that happens to players. It's a different scheme, different place to play. So I'm not totally down on Byron."

The Dolphins were counting on Williams and Maxwell to play crucial roles to help the defense take a step forward after ranking 25th in yards allowed per game last season. Instead, the unit has dropped to 28th in that category in 2016.

That's why Miami's playoff chances are already starting to slip away. It's going to take a major turnaround from the two marquee offseason additions for the defense to find consistent success over the remaining 11 games.