The sky over Southern California is not sunny today. Black storm clouds loom over Ed Burke Field at Torrey Pines High School in San Diego, where the living hope for the Arizona Cardinals’ upcoming season stands with his hands pressed against a goal post and his torso leaning forward, giving his legs a little stretch.

“I’m just trying to get warm and get this workout in before it starts thundering and lightning,” Carson Palmer says, flashing a smile. His face is covered in stubble, and many of those follicles are gray. “It takes me a little longer to get warm these days.”

That the 35-year-old quarterback is even on the field is a testament to the power of modern medicine and to Palmer’s work ethic and pain tolerance. Just seven months before, in a game against the St. Louis Rams, Palmer took a hit that destroyed his left knee, tearing his ACL for the second time in 8 years.

At the time, the Cardinals stood atop their division with a 7-1 record. But without Palmer, it all came crashing down. The team did well enough to squeak into the playoffs but didn’t make it past the first round.

“We all wish we could have had Carson,” said Cardinals cornerback Patrick Peterson. “We all know we could have gone deeper if we did have Carson.”

After undergoing reconstructive surgery in Arizona, Palmer started a rigorous rehab program of daily workouts, which sometimes ran for seven hours or more. Within a few months, the quarterback had made enough progress that he could return to his family’s off-season home in San Diego, where he continued his rehabilitation with help from trainer Ryan Flaherty of Prolific Athletes, physical therapist Derek Samuel, and skill coach Jordan Palmer—Carson’s younger brother.

“What I’ve seen the last six months is somebody who had something ripped from his hands that he’s trying desperately to get back,” the younger Palmer said. “That’s what’s driving him so hard this off-season.”

The Palmers and the rest of their training team gave STACK exclusive access to one of his grueling daylong sessions. When you see Carson suit up for the Cardinals this season, recall this taste of what it took for him to get there.

6:15 a. m. – Wake Up 

Palmer’s morning starts a little earlier than he’d prefer when one of his three small children wakes him up. He sits down for a quick breakfast—usually a meal that’s high in protein and packed with healthy fats—then spends a little time with his family before heading out to start the day’s training

7:15 a. m. – Arrive at Prolific Athletes

After a drive to Carlsbad, where Prolific Athletes is located, Palmer warms up by rolling out his muscles and performing a few light stretches.

7:30 a. m. – The Workout Begins

Training starts with footwork drills on the indoor turf field at Prolific. Palmer shuffles in and out of 10 cones while holding the football as if he were about to drop back for a pass. Although it’s been less than a year since his surgery, he doesn’t appear to have a limp in his gait. His footwork is fluid, crisp and steady.

“It’s pretty incredible,” Flaherty says. “Most guys who are that close to surgery, they don’t move like he does.”

The agility work is critical, because it dictates whether Palmer will be able to keep plays alive—and keep himself out of harm’s way—once the season starts.  He says, “Playing quarterback, you’re always on your feet—moving in the pocket, avoiding the rush, stepping up, rolling out quickly. All of the stuff we do on the turf is just to teach yourself to get into the right position to make an accurate throw.”

The start-and-stop nature of his movements and the side-to-side shifting can put tremendous stress on Palmer’s knee. But Flaherty has taken care to build his client up to the point where he can handle the movements, while also gradually increasing the challenge.

“Mentally, it’s about getting him over the block of, ‘oh, my knee can’t do this,’” Flaherty says.

From a strength perspective, they still have a long way to go. Flaherty says that Palmer’s quadriceps muscle in his injured leg atrophied following the surgery, and it’s smaller now. Also, Palmer hasn’t reached the level of lower-body strength that Flaherty likes to see in his athletes.

“For Carson, and anybody who’s trying to run faster, it’s about improving your strength-to-weight ratio in your lower body,” Flaherty says. “We’re trying to get him to where, in his Trap Bar Deadlift, he’s doing two-and-a-half times his body weight. Right now he’s at about 1.7.”

The workout also challenges Palmer’s upper body, which he knows will take a pounding this season. During the workout, he performs Push-Ups while wearing a weighted vest, does slow, controlled Pull-Ups, and performs arm and shoulder exercises using manual resistance, during which a partner pushes or pulls against his movements.

“The main thing I’m working on is just getting ready to stay healthy,” Palmer says, “knowing that it’s a 16-week season, then hopefully four or five weeks after that. Focusing on preparing to get landed on by a couple of 300-pounders, having them land on your shoulder at an awkward angle. And while you do all that, maintaining your flexibility so that you can stay limber and feel good.”

10:00 a.m. – Workout Ends 

Palmer isn’t done when the workout ends. He heads straight to the rehab specialist he’s been working with, Derek Samuel, who operates in La Jolla, about an hour south of Prolific. Palmer says the drive time is a chance to rest and refuel. “It gives me an hour of recovery in the car, [where I drink] a protein shake and take all my vitamins.”

11:00 a.m. – Rehab

Palmer is in what you might call an awkward position—back on the floor, knees bent, legs in the air. Each foot is strapped into a TRX handle, and Samuel has wrapped a thick rubber band around both of his feet. As Palmer pulls his heels toward his body, Samuel resists the movement. The quarterback grimaces with each pull.

“You have to be ready to attack every day,” Palmer says. “You have to be ready to be mad, and bored, and sick of doing the same thing every day. You just have to know that is what the situation is going to be, and get through it.”

Palmer, who was drafted No. 1 overall in 2003 by the Cincinnati Bengals, knows the repetitive grind of rehab all too well. He first tore his ACL in 2006, in a game against the then division-rival Steelers. The injury was called “devastating and potentially career-ending” by the surgeon who repaired his knee, but Palmer was back under center for the Bengals by the following pre-season.

Nearly a decade older when his recent injury occurred, Palmer knew the road back would be even tougher. From the outset, he sought to perform his rehab with top-notch professionals who were upbeat and encouraging. The process began at the Fischer Institute in Arizona, which is run by Brett Fischer, the Cardinals’ staff physical therapist.

“He’s super positive and always smiling no matter what’s going on around him, and that’s infectious,” Palmer says of Fischer. “He’s got his dogs in his physical therapy clinic. Just having that positivity around is huge for me.”

Today, at La Jolla Sports Club, Samuel begins by using his hands to feel for scar tissue or inflammation around Palmer’s knee. He then puts the QB through exercises that challenge his balance and his ability to rotate at the hips. Although Palmer is further along than most athletes at this point in the process, he is still not 100 percent, according to Samuel, who says, “He’s very far along for someone who would be 25 years old with only one ACL rupture, let alone someone who has two ACL ruptures at the age of 35. Carson does lack a little bit of internal rotation in his left hip. We know that if we increase that, we can minimize his risk for rupture.”

After the mobility work, Palmer performs several single-leg exercises on the leg press machine and with dumbbells. The weights are light, and the focus is on quality of movement—being strong and fluid through every part of the motion. The work is repetitive, and often looks uncomfortable. But Palmer doesn’t go easy on any rep. He says, “Once you’ve made the decision to come back, it’s a mental game. I’ve seen a lot of guys who have knee injuries that don’t ever get back. The biggest thing is mindset, knowing that you can’t take a day off.”

12:30 p.m. – Driving, Again

Carson’s rehab sessions typically last an hour and a half to two hours. At some point between noon and 1 p.m., he’s back in the car heading north. On some days, he can grab lunch with his family. On others, he heads straight to Torrey Pines High School to work on the field with his brother.

2:00 p.m. – On the Field

Younger brother Jordan is very much in control. He gives a signal. Carson follows. Then another. And another.

Jump. Shift. Move. Get through this speed ladder. Square up to this wiffle ball. Shift. Shift again. Throw.

Jordan says, “We’re training him to go from crazy different positions, but get right back to the sweet spot, where he can make the perfect throw.”

Carson and Jordan have been playing football together all of their lives. As Carson remembers it, they first started throwing to each other when he was 6 years old and Jordan was 2. Both brothers played quarterback at competitive high schools and colleges, and in the NFL. While Carson spent the majority of his career with a single team, Jordan played professionally under several coaches, and therefore learned many different systems. His combination of experience and in-depth knowledge of Carson made him an ideal coach to help his brother make his second comeback.

“He knows my mechanics,” Carson says. “He knows my throwing motion. He knows what I’m good at and what I need to work on. All of which has been a huge help for me.”

With gray clouds swirling overhead, the two progress from drill to drill, gradually increasing in difficulty. It’s similar to how Carson has progressed throughout his rehabilitation process.

“As he’s been getting more and more mobile, we’ve been adding more drills into the mix,” Jordan says. “The hurdles, the ladder, the med ball, the band around the ankles and the ankle weights—all of these have helped him to push his mobility to the limit.”

Throughout the session, Jordan challenges Carson to maintain the “triple threat” position, from which a quarterback can either step up in the pocket to avoid pressure, take off running, or throw a pass. In one drill, Jordan throws whiffle balls at Carson’s feet. When a ball hits the ground, Carson must turn his entire body in the direction of the ball while maintaining triple threat position.

It’s about tying your feet to your eyes,” Jordan said. “If your body is not lined up correctly, that’s the cause of like half the incompletions in the NFL.”

During throwing drills, Carson practices delivering the ball both with speed and with touch. His execution is nearly flawless. The session ends earlier than expected when the threatening skies finally develop into thunder and lightning, but Jordan leaves the field satisfied with Carson’s progress.

“When we first started working together, he could move this direction but not that direction,” Jordan says. “Now it’s different. Now it looks like he’s never been hurt.”

3:15 p.m. – Heading home

Palmer spends the rest of the day with his wife and children, trying to get in as much family time as possible before hitting the sheets at 9:00 p.m. Before bed, he spends a little time stretching to try and stay limber. He knows he needs to be smart about recovery and rest, so he can put in the work he needs to do tomorrow.

“Physically, this has been a grind, but the mental side of it has been surprisingly easy,” Palmer says. “It’s mentally easy because I have such a narrow focus right now. I’m so focused on this one year. People ask me how long I’m going to play. I’m going to play this year and see what happens. So throughout this, I’ve set one goal, accomplished it, then set the next. It’s been a great challenge, but I enjoy challenges.”