PHILADELPHIA -- Philadelphia Eagles tight end Zach Ertz once had a coach with a sensible solution for problems in the red zone.

“I think we’re going to start calling it the green zone,” Ertz said Thursday. “We’re done with the red zone. You can’t look at it as something where we’re going to stop. We’ve got to keep marching into the end zone.”

So far this season, the Eagles have been taking the stop-on-red thing just a bit too literally. They have scored touchdowns once they reach the red zone -- inside the opponents’ 20-yard line -- just 35 percent of the time. That’s the lowest success rate in the NFL.

For a coach with Chip Kelly’s reputation for offensive ingenuity, that’s not good. Kelly’s explanation?

“Turnovers,” he said. “You're not going to score any points in there. I think our mind set is you have three [points], we're greedy and we want seven. But you can't come away without anything in that situation. I think the turnovers are really the biggest part that's killing us in the red zone right now.”

In Arizona, wide receiver Josh Huff fumbled the ball away inside the Cardinals’ 10-yard line. Nick Foles threw an interception from the 25-yard line -- not technically a red zone play, but close enough. The Eagles amassed 521 total yards of offense, but generated just 20 points.

That is going to be a difficult trend to reverse Sunday in Houston. The Texans defense allows a fair amount of yardage, but opponents are scoring just over 20 points per game against them.

“They play good red zone defense,” Kelly said. “I think they are really sound. They don't they do a really good job of keeping the ball in front of them. I think they tackle very well in the secondary, so if the ball is completed there's not a lot of run after the catch. So it's a real disciplined group on the defensive side of the ball.”

The Texans play indoors, but crowd noise shouldn’t be that big a problem for the Eagles.

“We don’t really call plays in the huddle,” Ertz said. “We don’t have to worry about the communication factor in a noisy stadium. We just look at the sideline and get the play from there. I think that’s an advantage for us.”

One way Kelly can improve things in the red, er green zone is to involve Ertz more. The second-year tight end isn’t always on the field, because Kelly likes to accentuate the running game inside the 20. That means using tight ends Brent Celek and James Casey over Ertz. But as Ertz has evolved into a weapon, Kelly may need to find ways to integrate him more.

“That’s something I think I do very well, is get open in tight spaces” Ertz said. “In the red zone in particular, that’s something that I’ve done throughout my career, whether it’s in college or in the pros. Sometimes, it doesn’t matter who they put on me. I think I can get open. Hopefully my number gets called more.”