Twentyman's take: We're likely to see a lot of different combinations upfront among the defensive ends and tackles in Detroit's multiple-front scheme. Head coach Matt Patricia and defensive coordinator Paul Pasqualoni value versatility. The players that can play multiple roles and different techniques will have an edge.

Robinson led all Lions defensive tackles last year with 53 tackles. He also got his hands on six passes, including an interception he returned for a touchdown against New Orleans. He's entering his third season, and could be good as a two-gap interior defender. He's familiar with the techniques the Lions will play upfront from his time with defensive line coach Bo Davis at Alabama.

Williams, a former first-round pick, has 59 starts under his belt, and provides the Lions with experience and run-stuffing ability up the middle. Again, he's more of a run stuffer than pass rusher, which fits a two-gap scheme.

What the combinations look like upfront early in training camp will give us a better idea of how many defensive tackles the Lions will look to keep on the roster. Will they go heavier at defensive end based on scheme? Stay tuned.

By the numbers:

13: Passes defended by Robinson in his first two seasons in the league.

112.5: Rushing yards per game given up by the Lions' defense in 2017. That ranked 18th in the NFL last season.

56.8: The percentage of times opponents converted 3rd and short (4 yards or less) last season, which ranked in the top 10 in the NFL.

Quotable: "I think when you go through a season, and you have rosters that are limited, and you're only allowed to play with so many players active, that versatility is critical for all positions," Patricia said during Detroit's June minicamp.