ALLEN PARK, Mich. -- Since the Detroit Lions brought in former All-Pro cornerback Champ Bailey for a tryout last week, one of the biggest questions has been whether or not the team would end up signing him.

It doesn't sound like that is happening right now.

Lions coach Jim Caldwell said Thursday it was likely the team would fill the vacant roster spot left open from the season-ending injury to Bill Bentley with one of the two defensive backs on the practice squad: safety Nate Ness or cornerback Mohammed Seisay.

"We're in the process of determining what we want to do with it," Caldwell said. "It's not like we don't have a plan. We do. We're working on it. And so you have to anticipate and understand we're at Thursday, so the most likely thing that's going to happen is we're bringing somebody up.

"Nobody is coming in off the street and coming in and playing for us in the next few days, correct? So we're working on it."

Caldwell said he believes that this is "how the system should work" unless you're looking for a specific skill set and can bring a player in from the outside to fill that.

It would seem unlikely, though, that any player could come into Detroit and end up making an impact on Sunday against Carolina. Ness has more experience, having played in eight games over four seasons, making five tackles.

Seisay is the more developmental project and could end up being the better special-teams player.

"The thing I've learned is you can never have enough corners in this league," defensive coordinator Teryl Austin said. "But like I said before, the guys we have on the roster, they are guys that we feel comfortable with. They know our system, they know what we're doing.

"Like anything, if we can upgrade, if there's a chance we can upgrade, we'll upgrade. If not, we trust the guys we have here."

For now, it sounds as if the trusting metric will be the one the Lions employ.