Philadelphia Eagles v Arizona Cardinals

GLENDALE, AZ - OCTOBER 26: Free safety Earl Wolff #28 of the Philadelphia Eagles leads teammates onto the field prior to the NFL game against the Arizona Cardinals at the University of Phoenix Stadium on October 26, 2014 in Glendale, Arizona. (Photo by Christian Petersen/Getty Images)

(Christian Petersen)

PHILADELPHIA — Eagles starting safety Nate Allen missed practice again on Wednesday, a sign that he might not be on the field this weekend in Houston when the Eagles play the Texans.

If Allen can't play, the Eagles might be forced to turn to backup Earl Wolff, a player who did not get a ringing endorsement from head coach Chip Kelly.

"Earl’s been OK," Kelly said on Wednesday. "I think he needs to be a little bit more consistent from that standpoint, but he's OK."

When asked if he agreed with Kelly's assessment, the second-year safety shook his head.

"I don't feel like there is any concept I'm having trouble with," Wolff said. "In the preseason, I didn't make any mistakes."

The preseason is the last time Wolff has received extended playing time. He has played in just 16 snaps this season. That total is easily the lowest on the team. Every other member of the defense — besides Wolff and first-round pick Marcus Smith &mhash; has seen at least 100 snaps.

"I'm waiting on my opportunity to get out there and show what I can do," Wolff said. "I haven't gotten in a lot lately."

Kelly's less-than-stellar review of Wolff, combined with the fact that the team is bringing in a safety to work out on Wednesday, does not bode well for Wolff's playing time increasing any time soon — an aspect he is admits is frustrating.

"They don't tell us too much," Wolff said. "I go out there and play my game. I might mess up, maybe one time in practice, but that's going to happen. I feel like when I do mess up, I do a good job adjusting to where I need to be. Honestly, I don't have problems with the defense. I know the little details and the big details."

Kelly saying that Wolff needs to be more consistent and have a better understanding of the defense is nothing new. When the team re-signed Allen this past offseason to a one-year deal, it was viewed as a safety-net deal in case Wolff didn't win the starting job in training camp.

The two entered camp in a battle for the job, but it wasn't close: Allen practiced with the first unit for the majority of camp. Now, eight weeks into the season, Wolff might finally get his chance with Allen hurt.

Wolff said he is going to be ready if Allen doesn't play.

"I'm going to take full advantage of it," he said.

Eliot Shorr-Parks may be reached at eshorrpa@nj.com. Follow him on Twitter @EliotShorrParks. Find NJ.com Sports on Facebook.