KANSAS CITY, Mo. -- There was a point late in the summer when Chiefs defensive coordinator Bob Sutton must have wondered just who would be suiting up for him in the season opener in Houston.

Pro Bowl defensive tackle Dontari Poe was coming off back surgery. Standout safety Eric Berry had just finished treatment for cancer. All-Pro pass rusher Justin Houston was trying to land a long-term contract, and there was a very real possibility that he might hold out.

Fast forward to Week 1 and Sutton will have virtually a full defense at his disposal.

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Poe has been practicing despite missing all of training camp and the preseason. Berry was back at the start of training camp some 250 days after his diagnosis. And Houston signed his $101 million contract a week before reporting, ensuring he would be on the field Sunday.

All that's missing is cornerback Sean Smith, who is suspended for the first three games of the regular season for violating the league's substance-abuse policy.

Now, Sutton is ready to see how his defense performs.

"No matter how many players return, how many don't return, you're never really sure exactly what's going to happen until you get out there," he said Thursday. "Because you don't totally know your team and you're not exactly sure what's going to happen -- especially when something happens that maybe you don't want to. That's one of the processes of the whole thing, you find out."

The Chiefs thought they had an idea of what they were last season, only to incur season-ending Achilles injuries to Pro Bowl linebacker Derrick Johnson and defensive tackle Mike DeVito.

They still managed to be a formidable bunch, though. Kansas City ranked second in the league against the pass at just over 200 yards a game, and yielded just 17.6 points on average, tied with the Detroit Lions and trailing only the Seattle Seahawks for best in the NFL.

Oh, and Johnson and DeVito are back and healthy. That should only make the defense more stout as it prepares to face a Houston offense missing star running back Arian Foster to injury.

"I'm more anxious than anything. Not nervous, not scared, because I know that my body can hold up," Johnson said. "That's one thing I have to put out of my mind, which is very important for a guy that's been out for the whole season from an injury."

There is still some question whether Poe will play, and just how effective the 330-pound defensive tackle will be after back surgery. But he said Thursday that he's practicing as if he will play, and that "it just depends on how I feel toward the end of the week."

"It was something new to me," he said of the back injury. "It wasn't anything that I was welcoming, but it happens to pretty much everybody. This is the NFL. It happened to happen. I just took it one day at a time."

There is no such doubt that Berry will be on the field in Houston.

The three-time Pro Bowl safety has not appeared in a game since Nov. 20, shortly before he was diagnosed with cancer. And while he gradually worked into the mix during the preseason, Berry knows that everything changes with the start of the regular season.

"I kind of have this little vision for myself, where I want to be and how I want to help the team," he said. "Right now, it's not necessarily a milestone, it's almost like a checkpoint. It is a big deal, but I can't make it a big deal. I've pretty much just been going about my business every day and make sure everything is on point and that I'm sharp mentally and physically.

"If I put too much excitement behind it," he said, "I'll be real jittery and I wouldn't react good, so I'm just trying to look at it like one day at a time, one play at a time."