TEMPE, Ariz. -- When Kyler Murray returned home to Texas after his rookie season with the Arizona Cardinals, he took two weeks off to rest, recover and recuperate, then it was off to the daily grind of preparing for Year 2.

Waiting for him was his longtime trainer, Stephen Baca.

The two started working together when Murray was a sophomore at Allen High School and Baca was just beginning at Performance Course, the gym in Allen, Texas, that Murray has worked with in one way or another for the past seven years.

Together, while executing the training plan put in place by Cardinals strength and conditioning coach Buddy Morris, Murray and Baca replaced the weight Murray lost during the season, kept his legendary speed and added bulk that Baca hopes will make him more durable. Murray added somewhere between 7 and 9 pounds of muscle, Baca said. He also increased his flexibility and range of motion meant to prevent injuries.

Few, if any, know Murray's body like Baca. The two have developed a brotherly bond, all the way down to the smack talk in the weight room. Baca isn't afraid to call Murray a "prima donna" to his face but said it's all in good fun. In reality, Murray is as far from that label as anyone Baca has come across. Murray spends time at Baca's house, eating dinner with his family, playing with his infant son and regularly beating Baca at chess.

"He's like my older brother to me, family," Murray said. "As far as off-the-field, on-the-field issues, I can go to him with anything. He's family.

"So working with him, I'll probably work with him 'til I'm done."

And when Murray, the reigning NFL Rookie of the Year, showed up at the Performance Course gym in mid-January, Baca knew this offseason was going to be different.

Focus on football

For the first time since perhaps junior high, Murray -- the No. 9 overall pick in the 2018 Major League Baseball draft and No. 1 overall pick in the 2019 NFL draft -- had an entire offseason to focus on just football. As long as he played baseball, especially in college, he went from football season right into baseball season. And even though he didn't play baseball last season, he was busy with the pre-draft process, which took away from training.

This year was different. Completely different. Murray was "not trying to tear my body up" this offseason. He was all football all offseason.

Murray worked out four days a week with Baca at either 9 a.m. or 11 a.m. and threw two to three days a week with his father, Kevin Murray, a renowned quarterbacks coach in the Dallas area.

"It's been all football all the time, whether it's working out or throwing or studying film, and so I feel like he's still going to take some huge strides," Cardinals coach Kliff Kingsbury said.

"You think you saw a lot of that progression toward the end of the season and just speaking with him, his confidence level, his understanding of our system is night and day from where it was last year, and so we're really fired up to get him out there and try to take that next step this season."

All that put a little more pressure on Baca, who put into action a workout plan designed by the Cardinals' Morris. The two were in frequent contact all offseason about the quarterback.

"When you have somebody that's as talented as him, the focus is: Don't screw it up," Baca said. "Make sure he's maintained. If he was a car, make sure you change his oil, you keep it lubed up and you keep it ready for the race day. He's a monster.

"He's elite. So what you have to do with an elite athlete is you've got to keep them elite."

Maintaining Murray's speed

Murray is among the fastest quarterbacks in the NFL. His max speed of 20.09 mph last season was the fifth-fastest time among quarterbacks, according to NFL Next Gen Stats. He was one of five quarterbacks to have a run of 20 mph or faster and had the second-most runs of 15 mph or faster last season behind Baltimore's Lamar Jackson.

Baca was careful not to mess with one of Murray's most important weapons. Maintaining Murray's speed and quickness was both an art and a science. It was a balancing act for Baca to make Murray stronger but not to the point where it made him slower.

One way Baca did that was by using the force-velocity curve when handling Murray's speed. To maximize speed, Murray lifted lighter weights as fast as he could.

"That's what keeps the rate of force firing happening," Baca said. "His fast-twitch muscle fibers, the ones that he was already born with, it keeps those sharp."

To build his leg strength, Murray used a pit shark, a smaller, shorter machine used for belt squats around the waist instead of a traditional back-loaded bar squat. The pit shark "doesn't load your spine" and instead allowed Murray to squat with a hip-loaded action.

By lifting lower weights quickly, Murray was able to keep his reps in the four-to-six-second range, which is about the time of an average NFL play. Then his recovery between sets was about 40 seconds -- the time of an NFL play clock -- so his workouts mirrored what his body would be going through on the field during a game.

But Baca's best method for keeping Murray fast this offseason was to have him run fast. And to have him run fast a lot.

Depending on the week, Murray would run sprints totaling 100 yards, broken up into about eight sets -- so four 15-yard sprints and four 10-yard sprints, for example. Murray intertwined those with what Baca called "tempo runs," which were longer distances -- 50, 60, 70, 80 yards -- at 75% to 80% that were focused on working on his stride techniques. He also went through single-leg exercises, plyometrics, hopping, jumping, leaping and bounding workouts with Baca.

The ultimate goal, Baca said, is to make sure Murray will be as fast in the fourth quarter as he is in the first quarter.

'We're not after MVPs. We're after Super Bowls'

Baca said he remembered one morning yelling to Murray during a workout: "Kyler, let's get it! How you feeling right now? We're trying to be the MVP. Let's go!" Baca said Murray stopped, turned and responded, "We're not after MVPs. We're after Super Bowls."

Baca thought to himself, "Damn, that's exactly right."

To win a Super Bowl -- or even a playoff game -- Murray needs to make sure he's on the field at all times. The philosophy Morris handed to Baca was simple: Make sure Murray was as resistant to injury as humanly possible.

Even starting the season with some added bulk, injuries are bound to happen, Baca said. And one of the keys to Murray staying on the field will be his hamstrings.

Murray suffered a hamstring injury in a Week 16 win at Seattle last season that caused him to leave the game in the third quarter. The injury carried over into the season finale at the Los Angeles Rams. He was also listed on the injury report with a hamstring ailment in Week 13.

"He's always had really tight hamstrings, but that shows because he's so explosive," Baca said. "With somebody as explosive as him, you're going to have hamstring issues just period, because you're asking a lot of your hamstring to do."

To get Murray's hamstrings in proper condition to be the brakes he needed them to be, Baca had him do single-leg slides, glute bridges, band hamstring curls, single-leg RDLs, which is bending at the waist and lifting one leg in the air, and unilateral leg work.

Baca compared Murray's hamstrings to a Ferrari. When the sports car is going 100 mph, it takes more effort to slow down than when a regular car is going 65 mph.

"So when he does hit on the brakes, it's gonna require a whole lot more from him on the back side," Baca said. "So there's always been an emphasis for him to make sure that his hamstrings were strong and were able to handle the explosiveness.

"And his hamstring since the moment he's been explosive, they're playing catch-up. And I feel like they're finally caught up, because we've had an entire, you know, block of six months."

A 'bigger, thicker' Murray

Among the priorities this offseason was to get Murray's weight up a little, but it wasn't necessarily his intention to bulk up to the point where it'd become a topic of conversation.

He ended last season somewhere in the 196-to-198-pound range, Baca said, a product of a caloric deficit that most players deal with during a season. The goal was to send Murray back to Arizona for training camp at a weight at which he could afford to lose 10 to 15 pounds during the season and it wouldn't be an issue.

Baca guessed Murray returned to Arizona weighing around 205 pounds but "looks really big" through functional training. He didn't gain it the traditional ways, such as bench press or back squatting, Baca said.

"He's obviously put on some mass, and so he's bigger, thicker," Kingsbury said. "I think he understood it's a long season, you're going to take a bit of a pounding, and he wanted to bulk up in that area."

Murray's teammates noticed when he showed up in Arizona looking bigger. And pass-rusher Chandler Jones understands why.

"Yeah, Kyler is definitely bulked up," Jones said. "His arms and shoulders look a little bit bigger. He also has a tan. I also make fun of him, 'You have a tan,' but Kyler is definitely bulked up, and that's gonna be good for him, especially in this league.

"There's no quarterback that doesn't go through games without getting sacked. That's just the way it goes. He's fast, but when he has a little bit more meat on his bones, he can take hits, so that's going to be good for him."

"I saw him, and he looked a little buffer," said safety Budda Baker. "He's definitely thicker. ... He definitely seems faster, stronger arm."

Murray's teammates hype him up in the weight room because of his new bulk, wide receiver Christian Kirk said. But they're also impressed that a quarterback is willing to put his body through that type of weight training.

"It's good to see him because most quarterbacks aren't willing to go in there and bench and do biceps and whatnot," Kirk said. "But he's all about it. He gets after it in the weight room."

"I've always been a hard worker," Murray said. "I didn't try to go in the weight room and put on weight. I think it's just the maturation of getting older, working out."