Every once in a while, Detroit Lions linebacker Devon Kennard will flip on tape from an organized team activity practice last spring and compare what he sees then to where he’s at now.

The difference is stark.

“It’s definitely a huge growth,” Kennard said between appearances for the dietary beverage SOM Sleep last week. “I definitely see the evolution in my game and in my comfort level in this defense, and in my knowledge. I see it across the board with a lot of guys, though, and I want to continue to build on that.”

The Lions have been without key defensive players like Darius Slay, Damon Harrison and Trey Flowers this spring for either injury or contractual reasons, but the unit collectively is far ahead of where it was last spring in Matt Patricia’s first season as head coach.

That’s natural, of course. And while defensive coordinator Paul Pasqualoni insisted there’s little be gained from last year’s strong finish on defense – “When it ends, it ends. You start over again,” he said last week – Kennard is hopeful that having a year in the system will allow the Lions to pick up where they left off.

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“The nice part about minicamp is our meetings are longer, so we get to dive into nuances a little bit more and watch extra film,” Kennard said. “I think that’s just a part of the process and this offseason is essential for things like that. So I think we’re five OTAs down, pretty much halfway through OTAs, and we’re about where we need to be. But we got to keep pushing forward and take a good step the rest of these last two weeks of OTAs and minicamp and the whole deal.”

The Lions are one of nine NFL teams that host mandatory minicamp Tuesday-Thursday this week. No pads are allowed, but players can take part in up to 3.5 hours of on-field activity a day.

Defensively, Kennard and the Lions are largely a known commodity, even with several key players not on the field. Offensively, there’s a bit more mystery as the Lions are still installing new coordinator Darrell Bevell’s playbook, which is why that side of the ball kicks off my five minicamp things to watch:

All eyes on offense

In Week 1 of OTAs, the Lions spent a lot of time working on their red-zone offense. In Week 2, the focus was early-down situations. With two weeks of offseason workouts left, Bevell still has plenty more installation ahead as the Lions get ready for training camp. Matthew Stafford said he’s where he needs to be at this point of the offseason, but there are a lot of moving pieces to account for. Top receivers Marvin Jones and Kenny Golladay have yet to practice because of injuries, Frank Ragnow and Graham Glasgow are playing new positions, and tight end T.J. Hockenson is still getting indoctrinated to the NFL.

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Knock, knock

Who’s there? As in, which players will be taking part in minicamp and which players won’t. Harrison and Slay have forfeited $250,000 workout bonuses by not showing up to OTAs, and it’s unclear if they plan to attend this week’s mandatory workouts or incur $88,650 in fines for their absence. Beyond those two, Flowers, Jones, Golladay and Justin Coleman are a few of the key Lions who’ve spent the spring working with the rehab group as they come back from various injuries. Certainly, it’s wise to err on the side of caution with any player returning from injury, but it’d be nice to see some of the key Lions on the field as well this week.

What a Teez

With Slay absent and Coleman a limited participant, third-year cornerback Teez Tabor has spent plenty of time this spring working with the first-team defense. He’s had some moments both good and not-so good in the Lions’ two open OTAs, and he should get plenty of work again this week. The backup jobs behind Slay, Coleman and Rashaan Melvin are open, and Tabor needs a strong finish to the spring and even better training camp this summer to win a job.

Rookie watch

If the Lions are going to improve on last year’s 6-10 record, they’ll need big contributions from their rookie class this fall. Hockenson should see significant time at tight end, and as such the Lions are trying to make sure has one part of the position down before teaching him a new role. Second-round linebacker Jahlani Tavai and third-round safety Will Harris could be in the playing group, too, and this is a big week for all the rookies as they start to get a sense of what their days will look like come fall.

Surprise, surprise

There are surprise roster cuts and unexpected position battles that take shape every summer, and since they’re always a surprise it makes no sense to predict them here. But one under-the-radar player who’s worth keeping an eye on this week and into camp is punter Ryan Santoso. He Santoso has a big leg and the Lions were quick to sign him to a futures deal this offseason after he held his own in camp as an undrafted rookie. Sam Martin has two years and $5.7 million left on his deal, but Santoso is an NFL-caliber punter who’s fared well in the little bit we’ve seen this spring.

Contact Dave Birkett at dbirkett@freepress.com. Follow him on Twitter @davebirkett. Read more on the Detroit Lions and sign up for our Lions newsletter.