BUFFALO — The wake-up call came at 4:30 a.m., 15 minutes before sunrise Monday. Right away, United States Navy Seals instructors told 39 Sabres prospects to make their beds.

“That was the first time I’ve done that in a while,” winger Marcus Foligno joked.

The youngsters then got in a “proper line format,” going from tallest to shortest. By 5 a.m., they had reached a local beach, where they spent the next two hours swimming in the lake and doing crunches, push-ups, squats and other exercises.

“We did it like so many times, like 1,000 times we did it,” said center Mikhail Grigorenko, the 12^th overall pick last month.

When Foligno found out Seals, the Navy’s principal operations force, would be putting the prospects through the ringer, he started worrying and searched for more information.

“I saw some YouTube clips, and that just made me more worried,” Foligno said following the first day of summer development camp inside the First Niagara Center. “It wasn’t smart to do that. I tried to go to bed at 10 and I only went to bed at 1. That’s how scared I was.”

Foligno and the others made it through. Monday, however, was only the first workout. The Seals, the best of the best, will be waking them up the next three mornings.

How much harder will the Sabres have to work? Heck, could a helicopter get involved?

These are Seals, after all.

“I don’t know,” Grigorenko said. “We have (three) more days of that.”

Clearly, Foligno has a newfound respect for the Seals.

“We were tired, but those guys are 47 years old (and) can hold a crunch longer than we can, so it kind of made us look completely bad,” he said. “But they’ve been doing it a while. It’s just crazy to see how strong those guys are.”

Physical strength, of course, is just one small reason the Sabres brought the Seals in to instruct their prospects. The four-day camp is designed to teach them about all the rigors of professional hockey.

“The physical side of it, you’re going to get in great shape working with them,” center Cody Hodgson said. “More importantly, the mental side, you see some of the stuff they go through, the attention to detail they take to do their jobs.

“Hopefully, (we) take some of that and relate it to our job as well. We have a lot of respect for them – even more appreciation now.”

Foligno added: “It makes you understand how to push your mental ability, and how you can … teach your body that you’re not tired and to get out a couple more reps. Today we learned what it was like to be a Navy Seal and how hard you have to work.”

Their day was only beginning once they left the beach, though. The prospects still had on-ice sessions, and the first one featured three first-round picks – Grigorenko, Zemgus Girgensons and Joel Armia, the 16th selection in 2011 – practicing in Buffalo uniforms for the first time.

For Sabres fans giddy about the future, watching the forwards Monday offered a glimpse into what it might look like.

The 18-year-old Girgensons, a physical center the Sabres moved up to nab 14^th last month, has planned on attending the University of Vermont, where he’s currently taking summer courses. The Latvian’s AHL-eligible, however, and he’s considering turning professional.

“Nothing’s been clarified yet,” Girgensons said. “We’ll see what happens after camp.”

While Girgensons is seeking advice, he insists “it’ll be just my own decision.”

“I’ve asked a lot of people about it,” he said. “I’m not going to say what are their thoughts. … The decision I make is going to be what I want.”

What will Girgensons weigh?

“Something in me, what my heart’s going to say,” he said.

Meanwhile, Armia will play one more year in Finland before coming to North America in 2013-14. Right now, he’s about two months into serving his military duty, something he “can’t talk much about.”

“When the season starts … it’s kind of over,” he said.

The 19-year-old thinks playing another season in SM-liiga, Finland’s top league, will be beneficial. Most of the players are in their 20s or 30s.

“It gives you a little bit something when you play with men,” Armia said.

Notes: Grigorenko, who will likely be given every opportunity to make the Sabres out of training camp, said he’s already put on a few pounds since the draft. “I’m getting stronger. I feel more comfortable against big guys now.” … With a surfeit of defenseman, Brayden McNabb could be pushed back to Rochester next season, at least to start. The 21-year-old impressed in 25 games as a rookie last season. “I want to try to expect to be in the NHL,” McNabb said. … Hodgson, when asked about proving the Canucks wrong, skirted the question, saying, “I’m just happy to be here.” Vancouver general manager Mike Gillis, who traded Hodgson in February, said after the season he spent more time on the 22-year-old’s issues than every other player combined in three years.