The biggest among the myriad problems for the Raiders during their bye week has been the absence of a running game.
Oakland ranks dead last in the NFL in rushing at 60.8 yards per game a quarter of the way through the season.
It's a huge setback, considering the Raiders were self-advertised as a team that would lean heavily on the run and had finished second in the NFL in rushing in 2010 and seventh a year ago.
The hope was that running back Darren McFadden and the offensive line had come together in the previous week's 34-31 win over Pittsburgh. McFadden had rushed for 113 yards on 18 carries, opened the game with a 64-yard scoring run, and also had some tough short-yardage runs in the red zone.
A week later, McFadden was grounded again, gaining 34 yards on 13 carries against Denver. The Broncos were a team McFadden had abused in previous meetings, gaining 508 yards and averaging 7.3 yards per carry -- including a 150-yard, 22-carry effort in the 2011 regular-season opener.
So once again, the Raiders' switch to a pure zone blocking team was put under a microscope. McFadden had his most productive seasons when Hue Jackson introduced gap and power blocking, although injuries surely played a large factor in the first two non-productive seasons with a blocking system with Tom Cable as head coach.
Raiders coach Dennis Allen has said repeatedly he believes in the system from having to defend against it. Coach Greg Knapp likens it to a "start-up" company that will take some time. Offensive line coach Frank Pollack said during training camp that zone teams are better off being zone teams, without mixing and matching, with the "chaos" it produces.
However, following the Denver loss, Allen left the door open to re-evaluating Oakland's blocking schemes after a 1-3 start.
"We're going to evaluate everything," Allen said. "We're not going to stick our head in the sand. We're going to evaluate everything and see what things we need to improve on and where we can get better, and there's a lot of things that go into that. And we're going to go from A to Z. We got a lot of getting better to do, and that's what we plan on doing."
Whether the Raiders alter their style remains to be seen, but Allen made it clear there were more factors than blocking philosophy that were playing into the struggles, including a poor third-down conversion rate and falling behind.
"There's a lot of different things that are involved in it," Allen said. "When you're chasing points you're not able to run the ball consistently and therefore you're not able to run the ball effectively. There's a lot of factors that go into that and are involved in that, and that's what we got to do this bye week."
McFadden, averaging 2.4 yards per carry on all his rushes other than the 64-yard run, has made no pleas for a return to kinds of plays that helped him become productive in the previous two seasons.
"It's one of those things you know you've just got to keep running," McFadden said. "With the zone scheme, it's going to hit here and there but you have to keep running. Stick with it and keep pounding the ball."
Mike Goodson, a backup running back who looked like a good fit for the scheme in training camp, is not ready to abandon ship.
"I think you stick with it, man," Goodson said. "I think you stick with the scheme and you've got to get deeper into it. It's big on execution. From the outside, you can't see the small things.
"But there's a lot of stuff where we're one guy here, one miss there, if we execute, it will come around."
Goodson conceded being last in the NFL in rushing was not something he pondered in training camp.
"Definitely not," Goodson said. "It's not where you want to be. But we've got a lot of competitors in here and it's not sitting well with guys so we're definitely out there working."
When Allen was asked about McFadden being a non-factor, he said, "Well, if you ask the (defensive coordinators), they would say that he is a factor. When you look back at the end of the year, you're going to say Darren had success this year."