What to expect from rookies in defense

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Cornerback Carlton Davis

The Lions have made it a goal to overhaul their defense this offseason, and Davis was the first of four major acquisitions, arriving in a trade with the Tampa Bay Buccaneers in March. He allowed a career-high 8.8 yards per target last season, according to Pro Football Reference, but his length and physicality were a perfect fit for the Lions’ defense. Davis didn’t allow a single touchdown last season in individual defense, according to Pro Football Focus, and he should be the Lions’ No. 1 receiver this fall. He’s in the final year of his contract and has said he wouldn’t mind staying in Detroit, but he likely needs a strong season to make that happen.

Centre-back Terrion Arnold

Arnold missed part of training camp with a pectoral injury that defensive coordinator Aaron Glenn warned would limit his role early in the season, but the Lions traded up to get Arnold in the first round of the draft, believing he could be a long-term solution to their cornerback woes. Like Davis, Arnold is big and physical and thrives in man coverage. Starting cornerbacks tend to experience some serious growing pains early in their careers, so it may not always be smooth sailing for Arnold this season. But playing opposite Davis should give him time to settle in before he develops into what the Lions hope will be a career as a shutdown back.

Center defender Amik Robertson

The Lions used trades (Davis), the draft (Arnold and Ennis Rakestraw) and free agency to upgrade their defense this offseason, signing Robertson to a two-year contract in March. Robertson (5-foot-9, 183 pounds) lacks the size of some of the Lions’ other new signings, but he’s a versatile coverage guy who can flex outside or cover receivers in the slot. Robertson is expected to start the season as the Lions’ starting slot cornerback, with Brian Branch playing more as a true safety. He had two interceptions in each of the last two seasons and will be tested early by good slot receivers: Cooper Kupp of the Rams, Chris Godwin of the Bucs and Jaxon Smith-Njigba of the Seahawks.