In his first 16 NFL starts, the jury is out on the quarterback. Is he destined to be the cornerstone of the franchise or just another first-round draft pick who ultimately will fade away?

He struggles to complete passes downfield. He throws too many interceptions. He keeps fumbling. Sometimes it appears his biggest strength is running the ball, not throwing it.

Meanwhile, some critics are wondering if the team should start considering other options. Remember, he came out of an offensive system in college that bore no resemblance whatsoever to an NFL offense.

Marcus Mariota?

Yes. Him, too.

But this also applied to Steve McNair.

If memory serves, all of the above was the book on McNair after his first 16 starts with the Houston/Tennessee Oilers a generation ago. And it’s the same book on Mariota after his first 16 NFL starts for the Titans, including the 27-20 loss at Houston last weekend.

The growing pains are, well, painful. We see the potential, but we don’t see the consistent production. The interceptions are troubling. So is the penchant for fumbling. And why can’t he deliver the ball downfield?

Now, I’m not sitting here at a laptop saying that Mariota’s career ultimately will match or even exceed that of McNair. Maybe it will, maybe it won’t. It’s just too early to tell.

McNair is by far the best quarterback this franchise has had since it landed on Tennessee turf. Four games into his second pro season, Mariota remains very much a work in progress.

The point, of course, is that there were plenty of concerns about McNair’s performance as he was finding his way as an NFL quarterback. And many of those same concerns are now being attached to Mariota.

There are some noteworthy similarities in the statistics compiled by McNair and Mariota in their first 16 starts. McNair’s touchdown/interception ratio was 17/11; Mariota’s is 23/15. McNair lost seven fumbles in his first 16 starts; Mariota lost eight.

On the other hand, McNair was 9-7 as a starter during that period compared to Mariota’s 4-12 record. But let’s face it: The Titans were on the upswing in McNair’s formative years as starting quarterback. They were working their way up the division standings. They had perennial Pro Bowl players like Bruce Matthews on offense and Blaine Bishop on defense.

In contrast, these Titans are in the bottom quartile of the NFL in terms of quality and depth. They look like the weakest team of a woefully weak AFC South.

Mariota’s play is one of the reasons the Titans are 1-3 one-fourth of the way into the season. He has had a few good moments (the late-winning drive at Detroit among them), but his overall performance has been lacking.

He has not made the leap from his rookie year to his second pro season like many hoped. His passer ratings in the last two games are his worst as a pro.

Former Tennessee Titans quarterback Steve McNair shared many of the shortcomings Marcus Mariota has demonstrated during his first 16 starts. McNair became the franchise’s greatest QB and led the Titans to the Super Bowl.

-- Ap Photo/Tom Uhlman

This comes with the turf. The NFL is a minefield for young quarterbacks. Once opposing coaching staffs get some video of you, they start structuring defenses that take away the easy decisions and easy throws. The game changes.

In particular, Mariota is struggling to cope with blitzes. And defensive coordinators have picked up on it. In the Sept. 25 home loss to Oakland, Mariota had an 81.3 passer rating on plays when he was not blitzed but just a 4.9 rating on plays when he was blitzed, according to Pro Football Focus, which charts and grades every player on every play of every game.

Mariota has spoken about trying to do too much – holding onto the ball too long or forcing passes into tight windows.

While that is true, it’s also fair to say that he is lacking quality targets in the passing game. His most dependable and productive receiver is tight end Delanie Walker, who missed the Oakland game due to injury. Kendall Wright sat out the first three games with a bad hamstring before returning against Houston, where he was still limited.

Otherwise, the Titans receiving corps is nondescript at best. Rookie Tajae Sharpe has been a pleasant surprise, but a fifth-round draft pick shouldn’t be your best wideout.

Rishard Matthews has made a few plays. Andre Johnson is a future Hall of Famer but is playing for his third team in three years and is on the downward slide of a terrific career.

Meanwhile, Titans management gave up on former second-round draft picks Justin Hunter and Dorial Green-Beckham.

While I understand the frustration of watching talented players underperform, we must wonder if one or both of those guys could help in terms of stretching pass coverage with deep routes, something the current Titans receivers simply cannot do.

And then there is the way Mariota is being coached.

Say what you will about Ken Whisenhunt, but he had a knack for coaching quarterbacks. Yes, Whisenhunt’s pass protection schemes could be exploited (Mariota was sacked 14 times in the first four games last season compared to eight this season) but the coach and quarterback had a good working relationship.

Of particular concern is Mariota’s footwork in the passing game. Against the Texans, he often released passes without setting his feet. He was wild-high in a game where he completed only 13-of-29 throws. He was intercepted once and was lucky to avoid another pick or two.

Mariota is also caught in a bit of a quandary when it comes to Mike Mularkey’s offensive system. Mariota is much more comfortable in the shotgun and operating in hurry-up fashion, which is similar to what he did at the University of Oregon.

But Mularkey wants to run the ball and shorten the game, which means Mariota is often under center and letting the play clock tick down.

Given the current state of the Titans roster, the makeup of the coaching staff and the general lack of direction of the entire franchise, it’s much too early to determine where Mariota will go from here.

Remember, nobody knew quite what to make of Steve McNair after his first 16 NFL starts. After a decade without a true franchise quarterback, the Titans and their fans need to be patient with Mariota. This franchise has too many problems elsewhere to start a quarterback shuffle now.

Reach David Climer at [email protected] and on Twitter @DavidClimer.