NASHVILLE, Tenn. » Marcus Mariota feels much more comfortable going into his second season with the Tennessee Titans. The quarterback also is a little heavier.

The few extra pounds could help Mariota better handle the long NFL season.

“Sixteen games is a long season, and unfortunately I didn’t make all 16 last year,” Mariota said today. “That’s definitely a goal of mine to play all 16.”

Mariota and the rest of the Titans hit the field today for the first of Tennessee’s 10 organized team activities during their offseason program. The quarterback has a lot of new faces looking back at him in the huddle thanks to a busy offseason by new general manager Jon Robinson. Mariota also has a new offensive coordinator in Terry Robiskie.

Instead of an undrafted free agent taking his handoffs, Mariota now can give the ball to the NFL’s 2014 rushing leader in DeMarco Murray or the rookie who followed the quarterback in winning the Heisman Trophy in Derrick Henry. Mariota said Murray made a few cuts today that were pretty special.

“To have someone like that, a talent back there is not only going to open up a lot of run game stuff, but the play-action game as well as the pass game,” Mariota said. “To have that threat in the backfield will really make our team a lot more dimensional.”

That’s all by design.

The Titans are trying to better protect Mariota and give him more offensive help to keep defenses from teeing off on the quarterback who set a handful of franchise passing records as a rookie. Mariota was 230 of 370 for 2,818 yards passing and 19 touchdowns — all team records. He also had the longest run in the NFL last season at 87 yards.

But Mariota missed four games, including the final two of the season, because of injuries. He sprained each knee when hit in the pocket. So he added five pounds, pushing himself to 225 pounds after spending the first month of the offseason simply recovering from his rookie season.

Mariota said he’ll test himself through the remainder of the team’s on-field workouts to see how fast he is with the extra weight. He hopes to maintain his speed.

“That for us as an offensive hopefully will (be) another weapon, and I’ll try my best to kind of maintain that,” Mariota said.

That’s exactly what coach Mike Mularkey wants, having made it clear he wants Mariota running more since the quarterback can better protect himself in the open field. Tennessee also brought in another option at wide receiver, signing Rishard Matthews from Miami.

Veteran center Ben Jones was brought in to anchor an offensive line that gave up the most sacks in the NFL last season (54). The Titans drafted tackle Jack Conklin with the eighth pick overall out of Michigan State, and Conklin likely will start soon after veteran Byron Bell dislocated his left ankle today and had to be carted off the field.

Mariota said he trusts the coaches to make the best decision on who starts on the line. The quarterback who won the Heisman Trophy is focused more on trying to win games like he did at Oregon after the Titans went 3-13 in his debut season. Luckily, Mariota is a rookie no longer.

“Last season was brand new,” Mariota said. “A brand new city, brand new team. Now kind of being in it for a year, it’s nice to come out here and feel comfortable.”

Notes: The Titans have no names on the back of their practice jerseys. Mularkey said they want players to focus on the team name, an approach he’s familiar with from Pittsburgh and Robinson from New England. … WR Harry Douglas missed today’s session and will be back Wednesday after his daughter was born over the weekend.