Defensive back Rodney Harrison chats with Patriots owner Robert Kraft (left) and player personnel vice president Scott Pioli at yesterday’s training session.

THE Providence Journal photo / Bob Breidenbach Bob Breidenbach

FOXBORO — “We’re on the treadmill,” Bill Belichick said yesterday, after putting his Patriots through their paces in the first practice of training camp at Gillette Stadium. “We’re putting one foot in front of the other. We’ve got a lot of work to do.”

The coach was speaking figuratively. But veteran safety Rodney Harrison has literally been on the treadmill — and virtually every other piece of fitness equipment imaginable — while working hard to prepare for his 14 NFL season, and his fifth in New England.

“I’d wake up at 6:30,” Harrison said, “and the gym was calling me. I just couldn’t stay out of the gym. I’ve been working out two or three times a day. I’ve been playing basketball, doing yoga, doing Pilates — doing everything I possibly could do to get in great shape.”

Harrison is particularly eager to start this season because the last two ended prematurely for him.

After helping the Patriots win Super Bowls in his first two years after coming to New England as a free agent from San Diego, Harrison suffered a season-ending knee injury in the third game of the 2005 season.

There was some speculation, given the extent of the knee damage, and the fact that Harrison turned 33 that December, that it might be a career-ending injury. But he battled back, and was in the lineup on the opening day of last season.

He started the first eight games last year before breaking his shoulder against the Colts. He returned to start the last two games of the year, but injured his knee in the season finale against Tennessee and was sidelined for the playoffs. His absence was painfully obvious in the AFC championship game against the Colts in Indianapolis, when Peyton Manning shredded the Patriots’ secondary as Indy wiped out a 20-3 deficit and rallied to a 38-34 victory.

“I just want to stay healthy, so I can go out and make plays,” Harrison said, when asked his goals for this season.

Whether he still can make plays is not the question. He certainly can, if he can stay healthy. That is the real question.

“I know people are questioning if I will hold up,” he said after coming off the field following yesterday morning’s practice.

Harrison acknowledged that, for a time, he was questioning whether he should call it quits.

“When you wake up,” he said, “and you’re not feeling the way you’re used to feeling — you’re discouraged, and frustrated — that you think: ‘Man, I’m tired of this.’ But, once you get over the ‘pity party,’ it’s time to give yourself a pep talk and go to work.”

Harrison might not have the will to work as hard as he has to come back if the Patriots weren’t championship contenders.

“If we [were lousy], I might have considered [retiring,]” he said. “But when you have a great group of guys who are willing to sacrifice to succeed, of course you want to be part of that.”

Most veterans hate training camp. But not Harrison. Not this year, at least.

“When you’re young,” he said, “you don’t appreciate training camp. When you’re older, especially when your time is dwindling, you appreciate the sweat, and the soreness, and the camaraderie with your teammates.

“I love the blood, the sweat, the hard work. I love coach Belichick [swearing at] us. Sure, you get tired and sore. You fall asleep in team meetings, and coach catches you, and you try to pretend you were paying attention. But because I’ve been injured, and am in my last years in the league, I really appreciate all this. I know time is running out on me.”

He also knows that many people are picking the Patriots, who lost in the AFC championship game at Indianapolis last year, to make a strong run at winning another Super Bowl — their fourth in seven seasons.

“It’s good to look at the roster,” he said, “and say: ‘OK, we’ve got Randy Moss. We’ve got Adalius Thomas. We’ve got Wes Welker.

“But the Tedy Bruschis, the Mike Vrabels, the Tom Bradys don’t give a darn about where people think we should be. We know we have a competitive team. Whether that results in 10 wins, or 12, or 14 — who knows?”

Here is what Harrison does know: “I’m excited to be playing. I feel good. I have confidence. And I want another championship.”

Harrison enters this season as the NFL’s all-time leader in sacks by a defensive back, with 28.5. He also is the only player in league history to have recorded at least 25 career sacks and at least 30 interceptions (he has 32.)

If he can stay healthy this year, that will greatly enhance the Patriots’ chances of winning another title.

jdonalds@projo.com