ALLEN PARK -- The Detroit Lions continue to shake up their defense following a humbling loss against the Cleveland Browns. Only this time they didn't add a guy.

They just promoted one.

Rookie cornerback Darius Slay was elevated to the first team for both weekend practices following a 24-6 loss Thursday against Cleveland. He's playing on the right side, a position that had been held by veteran Ron Bartell.

Darius Slay, right, defends a pass intended for Micheal Spurlock during a recent Detroit Lions practice.

The second-rounder out of Mississippi State now is looking like a good bet to start Thursday against Tom Brady and the New England Patriots (7:30 p.m., WXYZ-TV).

"There were some guys in the first couple preseason games that we wanted to get more reps," coach Jim Schwartz said. "We really don't have depth charts right now, but we do have rotations. He's getting some good reps, but that's because of his play in the preseason games. The greatest reward is the opportunity to do more."

Slay wasn't targeted at all agains the New York Jets, and just once last week against the Browns. He made three tackles.

His man-coverage skills have been particularly impressive, even in one-on-one drills that are designed to favor the receiver. He said his progress was slowed slightly earlier in camp after the Lions tweaked the technique he learned at Mississippi State, but he has felt increasingly comfortable in the past few days.

Now he's trying to develop his press-coverage technique.

"He's patient in his press technique. His man-to-man coverage is good," Schwartz said. "There are still a lot of things like a lot of the rookies. There are still a lot of things that he's still working on and trying to improve on."

Ironically enough, it's Bartell who has helped the rookie.

"He's like a great uncle to me,'' Slay said. "He taught me a lot scheme-wise -- what comes with this route, what comes with this release. He's helped me a lot.''

That growth appears to have elevated Slay onto the first unit for Detroit's third preseason game -- often the most important exhibition, as lineups are set heading into the mostly meaningless fourth game.

In other words: Starting Thursday would be a giant step toward beating out Bartell for the starting gig Week 1 against the Minnesota Vikings.

And that's quickly becoming the expectation around Allen Park.

"What I'm going to do is continue to do what I'm doin', and continue to get better," Slay said of the battle. "I've always been comfortable. I'm always confident in what I do and who I'm going against (in job battles).

"I ain't never had any worries competin' with nobody."

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