The Vikings practiced in pads for the fourth time during training camp on Saturday in one of their longest sessions of the week. After a Sunday walkthrough, they will be back in pads Monday night for their annual practice in TCO Stadium.

The stretch certainly would not match the intensity of camps from the Vikings' early years in Mankato, or even the ones coach Kevin O'Connell and defensive coordinator Brian Flores can remember from their first season together in 2008, when two-a-days were still allowed under NFL rules and commonplace in New England under Bill Belichick.

But it represents a departure from the Vikings' typical practice structure during O'Connell's first two seasons. The team categorizes practices as either high, medium or low intensity; their camp schedule often followed a rotation to give players recovery time after a strenuous practice. This season, O'Connell said, the Vikings' workload at the start of padded practices needed to look different.

"We buckled up and had three significant days," O'Connell said Friday. "I know only two of them were in pads, but that Tuesday practice was significant; there was some situational work. I've got a plan of how I want to push these guys. It will always involve over-communicating expectations on the front end, challenging the guys to lock in on sequences of training camp. We're about to start another one right now."

O'Connell hopes the work will mold a Vikings team he wants to be more physical this season; the team signed former Packers running back Aaron Jones to spearhead a running game that could employ more power runs to spring the veteran free. Defensively, the Vikings ranked eighth in the league against the run last year but allowed a combined 320 rushing yards in a pair of pivotal December home losses to the Lions and Packers. They will field a remade linebacking group this season; several roles on the defensive line remain in play.

The team has typically taken a careful approach to training camp, adjusting player workloads with GPS data checks and executive health director of player health and performance Tyler Williams' input. That's still happening; it led to Justin Jefferson getting a rest day on Wednesday after data showed how much he'd run and how much water he'd lost in several days of hot afternoon practices.

But in his third camp, O'Connell is trying to maintain a fresh roster while instilling work he hopes will refine players.

"In a lot of ways, it's gauging the dialogue with that player, what the medical folks are saying, what the doctors are saying, and then crafting a plan for that player while knowing I've got to get the football team ready to go," O'Connell said. "It's part of my job this time of year to gauge how to prepare the team while also making sure we've got a team to prepare."

Even with Jefferson's elevated status, it's rare for the receiver to miss a practice, and of the day off, he said Friday, "I like it and hate it at the same time.

"Just because I never really was the type of person to take days off," he said. "But I understand I'm starting to get a little older, and the yards I'm running and the way I'm running every single day of practice, it starts to take a toll on me, you know? So it's just taking a little step back."

Jefferson, who missed seven games because of his right hamstring injury last season, said he's "so scared" of injuring his hamstring again, adding he focused on strengthening his hamstrings this offseason to prevent further injury. O'Connell said Jefferson "learned a lot about his body" from the injury, adding, "I think he's done everything possible to have himself ready to go."

"But we want to make sure Justin plays a lot of snaps for us. We want to make sure his training camp progression is the right kind of progression coming off a first-time [injury] for him."

If science helps the Vikings manage the health of players like Jefferson more carefully, the setup of the modern game means teams prepare for a longer season under more constraints. League rules limit teams to four hours of on-field work during camp, with caps on the number (16), length (2½ hours) and frequency (no more than three consecutive days) of padded practices.

At the start of Flores' career, "it was two-a-days then. So a lot more practice, a lot more fundamental work, just a lot more of everything. More opportunities for guys to get reps, and they can just get better by doing it over and over again. But everybody's working with the same rules [now]. And I talk to our staff about being efficient with our time. I'm constantly trying to tweak it, saying, 'Can we get five minutes here, or two minutes back here?' That's a constant work in process."

Before two joint practice days against the Browns' stout defense later this month, the Vikings are injecting a little more intensity into their camp in Eagan, in hopes it will produce a team with the grit O'Connell wants.

"That's why we have to make sure these padded practices are physical," O'Connell said. "We have to make sure the competition makes both sides of the ball better each and every day."

Etc.

• The Vikings remained without cornerback Shaq Griffin and safety Lewis Cine because of injury on Saturday. Wide receiver Malik Knowles, offensive lineman Jeremy Flax and linebacker Bo Richter did not practice, while linebacker Gabriel Murphy and tight end N'Keal Harry left early. Defensive end Jerry Tillery was carted off the field after being injured during a drill.

• Rookie quarterback J.J. McCarthy rebounded from a tough day on Friday, hitting Trent Sherfield in the back of the end zone for a touchdown and trading a midair hip bump celebration with Nick Muse after he found the tight end for a big gain on a seam route.