Reiff (left) signed a deal with Detroit. (US Presswire)

Slowly but surely, teams are locking down their first-round draft picks. The latest is Lions offensive lineman Riley Reiff, who reportedly signed a deal with Detroit.

Tim Twentyman of DetriotLions.com reports that Reiff has signed his deal and will report with the rest of the rookies when Lions rookie minicamp begins on Monday.

Reiff, chosen with the 23rd pick in the 2012 NFL Draft, is expected to have an immediate impact on the Lions. He's the long-term replacement for left tackle Jeff Backus, but isn't unlikely to unseat the long-term blind-side protector this season. Instead, Reiff will likely compete for the right tackle job and, because he's in camp on time, stands a good shot at winning that gig. Worst case, he could shift to a guard position and/or provide depth for the line.

There are now nine unsigned first-round picks: Trent Richardson and Brandon Weeden of the Browns, Matt Kalil of the Vikings, Justin Blackmon of the Jaguars, Morris Claiborne of the Cowboys, Dontari Poe of the Chiefs, Kendall Wright of the Titans, and David DeCastro of the Steelers.

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