NASHVILLE, Tenn. -- Through 15 career starts, Marcus Mariota's glaring weakness is turnovers.

He’s thrown 14 interceptions and lost eight fumbles. On a young team trying to climb out of the NFL’s basement, it’s a big part of why they are still waiting on the elevator.

In three games this season, his turnover issue has gone well beyond that of his rookie year. He’s thrown four touchdown passes to go with four interceptions and two lost fumbles.

“I think it's a combination of a lot of things,” coach Mike Mularkey said. “I would like to see our receivers help him out and make some plays on contested balls, like I see across the way. That's one. I think maybe earlier, with the interceptions, it was a little bit of trying to make something happen because he is confident in his ability. Again, I'm not going to take anything back from him. He's made some of those same throws and completed them.”

Marcus Mariota has turned the ball over 22 times in 15 career starts. AP Photo/James Kenney

Mariota needs to make an adjustment where he doesn’t try to force things but doesn’t allow the additional caution to restrict his game.

“It’s smarter decisions,” he said on The Wake Up Zone in Nashville. “You know, when it comes down to it, a lot of times I am trying to win the game with one throw or trying to win the game by doing too much or trying to run for a first down rather than just letting the game come to me, making smart decisions with the football and making sure that we don’t put our defense in bad situations.”

In 11 losses, he’s thrown 12 picks, fumbled 12 times and lost seven of them.

In four wins, he’s thrown two picks, fumbled once and lost that fumble.

On his most recent fumble, Mariota was trying to convert a third-and-13 on which he gained 9 yards.

“I know he's trying to get to the line, but again, we've been pretty thorough about ball security with him when he gets outside the pocket,” Mularkey said. “That's a tough lesson, again, to learn. We're going to stay on it until he starts doing it. We're going to stay on him about it, but those are things I see him trying to do more is when he's got the ball in his hand.”

Mariota has to do better.

His coaches can do better too, getting him into situations where he is more comfortable more often.

Since Mariota has been the team’s starting quarterback, the Tennessee Titans are 2-1 in games in which they won the turnover battle, 1-5 in games it was even and 1-9 when they gave the ball away more.

It’s one of football’s simplest principles. The team that loses turnovers usually loses the game.

The Titans have to get on the right side of it a lot more often and that starts with Mariota.