SEATTLE — Greg Gaines never did get used to the whole injury thing.

The Washington Huskies defensive lineman had never been seriously hurt in his football career, but had to sit out spring practices this year after sustaining an injury while lifting weights.

As he watched spring practices from the sidelines, his left arm in a sling, Gaines had to resist the instinctual urge to run onto the field with his fellow starters.

“It was definitely strange standing there,” Gaines said Monday. “Coach would call ‘one base,’ and I’d be ready to run out, and I would be like, ‘wait a minute.’ So it’s been different. But I was just getting my strength back and getting ready to go for this season, which is what matters.”

What also matters: the Huskies began fall camp on Monday with a 90-minute workout at the Dempsey Indoor facility, wearing only shirts and shorts and shoes with no helmets and no pads. They revisited fundamentals like footwork and quarterback-tailback handoffs. They gathered for some 11-on-11 work, but mostly used their first preseason practice as a refresher course for many things they have already done, as coach Chris Petersen’s teams always do this time of year.

Petersen, of course, warns that despite the Huskies’ banner 2016 season, despite the talent they return after winning 12 games and the Pac-12 championship and appearing in the College Football Playoff, they won’t be the same team in 2017. Five defensive starters departed, four of those drafted by NFL teams. (Star receiver John Ross III is gone to the league, too.)

Yet there is a sense among those returning, particularly on defense, that a drop-off isn’t only avoidable, but unlikely. Different doesn’t have to mean worse.

“I don’t see any holes in our defense,” said fifth-year senior linebacker Azeem Victor. “Everyone is ready to go out there. Everyone is ready to play. I can see that. Just being around these guys, even in the summer, just their mindset of how they worked out, I can tell that they’re ready to roll.”

As Gaines noted, the Huskies return Victor and fellow fifth-year senior Keishawn Bierria at linebacker, and Gaines and fellow fourth-year junior Vita Vea — a potential top-10 draft pick in 2018 — anchor a defensive line that should again be stout against the run after leading the Pac-12 in yards-per-carry allowed last season.

“They expect us to be the same team we were last year, the same defense,” Bierria said at Pac-12 media days. “We’re going to look totally different, because we have a new group of dudes coming in, and it’s going to be special.”

The biggest question is in the secondary, where the Huskies bid farewell to a trio of second-round draft picks — cornerbacks Sidney Jones and Kevin King, plus safety Budda Baker — following last season’s breakthrough. It would be difficult to fathom a scenario in which the Huskies experience zero drop-off from that crew to the new one, though that transition is aided some by the presence of safeties Jojo McIntosh and Taylor Rapp, both returning starters.

Plus, defensive backs coach Jimmy Lake said, the new guys should be pretty good, too. Junior Jordan Miller and redshirt freshman Byron Murphy are in prime position to lock down the two starting corner spots, and there should be fierce competition for the fifth starting spot in the defensive backfield — whether that’s at nickel or somewhere else. Senior safety Ezekiel Turner is one of the team’s biggest hitters. True freshman Elijah Molden will get a chance to earn immediate playing time. Sophomore Myles Bryant — the former walk-on is now on scholarship — could see the field plenty, too. So could third-year sophomore Austin Joyner, a Marysville Pilchuck alum.

“I think this is going to be one of the most competitive camps we’ve ever had. I told that to those guys about five hours ago, in our first meeting,” Lake said. “I am very, very excited about this group. I think they’re all going to push each other. They’re going to hold each other to a high standard.”

On Monday, the Huskies wore shirts with the word “Hunt” printed on the front.

The meaning, Victor said, is simple: “Going out there and trying to do what we did (last year) one more time, and even better.”