Matt Jones, right, did not attend the Redskins’ voluntary offseason practices, but was on hand Tuesday for minicamp. (John McDonnell / The Washington Post)

Before practice began in earnest on a sweltering opening day of minicamp, Washington Redskins quarterback Kirk Cousins and Pro Bowl left tackle Trent Williams traded a football players’ hello: A slap of hands, followed by a helmeted head-butt.

Later in the session, the first-team offense was on the 25-yard line, just seconds remaining in a two-minute drill, when Coach Jay Gruden barked out third-and-10 as if the postseason hung in the balance. Cousins dropped back, surveyed the defense and threw a beautiful ball to tight end Jordan Reed, who slipped past the linebacker and grabbed the touchdown pass.

“He’s b-a-a-a-ck!” Cousins exulted, thrilled to have the Redskins Pro Bowl tight end back on the field.

Tuesday marked Day 1 of a three-day, mandatory minicamp at Redskins Park, as well as the return of Williams and Reed — linchpins of Washington’s explosive offense in recent years and integral to Cousins’s success.

Both had skipped the team’s voluntary workouts over the three preceding weeks, opting instead to get in shape with personal trainers elsewhere —Williams, 28, in Oklahoma, and Reed, 26, in Florida. Both had notified Gruden of their plans, unlike third-year running back Matt Jones, who was simply a no-show, disgruntled about his mid-season demotion and mounting evidence he was no longer in the Redskins’ plans after fumbling for the eighth time in 20 career games.

As temperatures climbed to 95 degrees Tuesday, with the humidity making it feel like 99, no one wasted energy holding a grudge.

The status of Williams and Reed is not in jeopardy. Williams, a five-time Pro Bowl honoree and longtime captain of the offense, is the anchor of a Redskins offensive line that allowed just 23 sacks last season (fourth fewest in the league). And Reed, at 6 feet 2 and 246 pounds, is a perennial mismatch for defenders.

Reed — who missed four games last season after suffering his fifth diagnosed concussion, as well as a separated shoulder — slipped effortlessly back into his role as the Redskins’ featured tight end Tuesday, connecting often with Cousins.

“Jordan had a pretty good day; he had about 11 catches,” Gruden said, chuckling at the hyperbole. “You just feel good seeing Trent over there at left tackle. We’ve had guys step up without them, but it’s great to see them.”

Reed said after practice he felt strong and explosive after a rigorous off-season workout regimen at South Florida’s Legacy Fitness that consisted of cross-training, weight-training in the mornings and footwork drills each afternoon.

“I just wanted to rehab my shoulder and get my body right and see what I can do,” said Reed, whose first two NFL seasons were hampered by injury. “I feel great.”

Jones, a third-round draft pick in 2015 who was touted as the future of the Redskins’ running game, explained he had stayed away from optional workouts on his agent’s advice, spending the time working out in Tampa and mulling over potential landing spots if the team released him heading into his third season. He hadn’t been slacking, he wanted his coaches to know.

Jones said being back at Redskins Park this week, laughing with his teammates and competing alongside them once again, stirred his passion for a place on the team.

“Now that I’m here, honestly, I still feel I’m back at home with the Redskins,” said Jones, who was slotted with the second-team offense, getting his carries after rookie Samaje Perine, the broad-shouldered, powerful back from Oklahoma whom the Redskins drafted in the fourth round.

“It felt good to be back; I missed it,” Jones said. “I told my running back coach Randy [Jordan], ‘I missed it,’ and he told me he missed me too. It felt good. It felt like I never left. It felt good to be out here watching guys making plays and see how far everybody progressed.”

Jordan urged on Jones Tuesday as if he were every bit an essential team member. “Get out there! Go!” Jordan shouted, as Jones ran a pass pattern, caught the ball and took off up-field. “I like that, 31! I like that!”

Jones added that he was “ready to do whatever it takes” to get his starting job back, special-teams play included, if coaches would consider it. “Who says I can’t be a starting running back?” he asked.

Asked afterward if Jones had a shot at reclaiming his starting job, Gruden said that it boiled down to competition among a deep complement of backs.

“Guys who make plays and guys who are productive are guys that I like to play, it’s no secret,” Gruden said. It would be tough, the coach added, to displace a player who’d taken part in every workout and done well, citing the impressive efforts of incumbent starter Rob Kelley, Mack Brown, rookies Perine and Keith Marshall, as well as third-down back Chris Thompson.

“It’s a really tough position to crack, but I wouldn’t put anything past Matt,” Gruden said. “He’s a big, physical guy.”

The Redskins return for on-field work Wednesday and then break until training camp gets under way in Richmond on July 27.