NASHVILLE, Tenn. -- An upbeat Marcus Mariota said he thinks he will be running full speed in two to three weeks and will be the same quarterback he was for the Tennessee Titans when he fully returns from the broken right fibula he suffered on Dec. 24, 2016.

"There are great things here that have allowed me to push the envelope a little bit, whether it's jogging, or doing some other stuff on the AlterG [anti-gravity] treadmill and stuff like that," he said on the first day of the team's offseason program.

When he flew from Charlotte to Nashville shortly after his January surgery, Mariota set off the metal detector at the airport because surgeons had inserted a plate in his leg. Now, he's not feeling any pain as he works his way back from the Week 16 injury suffered against the Jacksonville Jaguars.

"It's more kind of working back those muscles that were stagnant for two months I was in a cast," he said during his first news conference since the injury. "It's kind of rebuilding those foundations back up, and I think we are in a good place ..."

"It's fun to get back in here, see the guys and get football going again."

Coach Mike Mularkey said he's glad to see his quarterback, who did a share of his rehabilitation in Oregon. The Titans have said they will be cautious and plan to hold Mariota out until the start of training camp, turning things over to backup Matt Cassel in the meantime.

QB Marcus Mariota said on Monday he's optimistic he'll be fully healed from his broken fibula when the season starts. "I think we are in a good place...it's fun to get back in here, see the guys and get football going again." Reinhold Matay-USA TODAY Sports

Mariota said he's not patient, but knows what may be necessary.

"I understand that I've got a lot of time to get my body right and that's my goal," he said. ".... "Maybe another two to three weeks [until I am jogging]. Hopefully. I can't give you an exact timetable. That's the benchmark I am aiming for."

When he first got hurt, Mariota said he felt like he simply rolled his ankle. When teammates helped him up, he said he "realized it was maybe more severe than I originally thought."

"If I can talk, I do my best to get up and walk," Mariota said. "At that point in time, I couldn't."

Adrenaline kicked in and it wasn't super-painful, he said.

The first month of his recovery included a lot of video games played online with friends, featuring Call of Duty and Battlefield, but no Madden.

Now each step of the rehab process feels good, he said, and it's gratifying to "feel the progress kind of every day."

DeMarco Murray said he's got confidence the hard-working third-year quarterback will do all he can to be ready when he can. The running back has caught passes from Mariota a few times.

"Routes on air, he looks good to me," Murray said.