NASHVILLE, Tenn. -- For about a month early in the offseason, and then again in July, Marcus Mariota spent time with San Diego-based strength and conditioning coach Ryan Flaherty.

Their mission: Work to make the Titans' second-year quarterback less susceptible to injury.

Mariota had a fine rookie year but played in only 12 games as two separate knee injuries knocked him out of action.

Bad luck and bad timing can make some injuries unavoidable.

But Flaherty said Mariota worked hard to improve muscle groups that are important for stabilizing knees that might take lateral hits: hips, gluteus medius (the muscle that’s on the outside of both sides of the pelvis) and VMOs (vastus medialis obliques), the teardrop muscles above the kneecap.

“A big part of injury prevention is you’ve got to be able to get to the smaller stabilizer muscles, and we really focused on building those up,” said Flaherty, who has worked with quarterbacks Carson Palmer, Russell Wilson and others. “At this level you take more hits, more contact to the lower body, knees, and we really focused on stabilizing the knee joints and working on his hips."

Most of the strength training comes in the form of exercises using the athlete’s own body weight.

Mariota showed me one: Standing on one foot, he was lightly toe touching with the other foot to the front, the side and the back.

“The VMOs’ main job is to stabilize the knee joint, especially when you’re taking hits from the side through the entire year,” Flaherty said. “You saw with Marcus last year he took quite a few of those. The more stable and strong that VMO is, the more stable that knee is.”

Mariota’s connection with Flaherty dates to before the 2015 scouting combine. Mariota’s parents sought out the trainer, making the initial connection.

“He’s been great,” Mariota said. “From the second I finished school, he was a guy I was working out with, getting ready for the combine, getting ready for my pro day and all that stuff. I’ve constantly gone back to him. I think the world of him. I think he’s made me a better athlete. And I’ll continue to work with him for years to come."

Such a relationship is more necessary now, as the CBA between the league and the players says a player can’t be with a strength coach like the Titans' Steve Watterson for about three months after the regular season and for five or six weeks in the summer.

Flaherty said he texted Mariota after he suffered his first knee sprain -- Oct. 18 against Miami on an illegal hit from Olivier Vernon -- and said he’d seen less torque and twisting result in a torn ACL.

“He would send me text messages throughout the year,” Mariota said. “'Make sure you’re working on your VMOs, make sure you’re building your body up the right way.’ When I got to him this offseason we talked about how the injuries happened. I was a little lucky, for sure.”

Perhaps some of their work helped lessen the impact. Perhaps in the future, additional work will do the same or more.

Mariota agrees with the idea that staying healthy as an NFL quarterback is partly a skill.

“Part of it is playing smart,” he said. “Sometimes it is luck. But at the same time, if you work hard at it throughout the offseason, you give yourself a better chance of staying healthy."