For the first two and a half years of his career, the Detroit Lions used Quandre Diggs, their fifth-round pick in 2015, mostly as a rotational cornerback. Last season, however, the Lions shifted him to safety midway through the year. The move paid dividends for both sides. Diggs fared well on the back end of Detroit's defense, and on Monday, the team rewarded him handsomely with a three-year contract extension. 

According to a report from NFL Network's Ian Rapoport, the deal will pay Diggs $20.4 million over those three seasons. 

Diggs is headed into the final season of his rookie contract, which will pay him a base salary of $1.907 million during the 2018 season. He was set to hit unrestricted free agency next offseason, but instead he will become a stalwart on new coach Matt Patricia's defense. 

The safety market was incredibly slow this offseason, with starter-quality players like Kenny Vaccaro and Tre Boston languishing on the free agent wire for months before being signed at steeply discounted prices, while Eric Reid still has not been signed. Diggs' deal finally pushes that market forward a bit, even if he does not come in at or near the top. (He'll be the 15th-highest-paid safety on an average annual basis, per Spotrac.) 

The Lions now have Diggs and star cornerback Darius Slay both locked in through at least 2020, while Glover Quin, Nevin Lawson, and Tavon Wilson are all signed for 2018 and 2019. The team still needs to make upgrades on defense in order to take the next step forward but that is at least a solid secondary on paper, with a shutdown corner and two above-average safeties holding things down.